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  • 1.
    Ahluwalia, Arvind
    Mälardalen University, School of Innovation, Design and Engineering.
    Computer Controlled Direct Descent2017Independent thesis Basic level (degree of Bachelor), 180 HE creditsStudent thesis
    Abstract [en]

    How an aircraft performs its approach and descent towards an airport today has got big potential for improvements. It's mainly the environmental impact and safety that can, and must, be improved for a sustainable future in aviation. "Green Approaches" is a small, yet relatively well-known, optimized approach system mainly used by Scandinavian Airlines on Arlanda airport. Unfortunately "Green Approaches" aren't used often enough, due to the simple reason that it doesn't work very well during heavy traffic. Luckily further research is being done in this field to further optimize an aircraft’s approach. As of today, the most forward going research is being done by the FAA and NASA, and their new system is called NextGen OPD. The system is not fully developed yet but their goals are, as previously mentioned, to optimize today's aircraft approach. In this report the focus will also be set on improving aircraft approaches, although not by optimizing today’s system like the FAA and NASA. Instead, a whole new concept of how aircraft approach airports will be developed. The reason that a brand new concept will be developed is simple, optimizing today's aging system will not be sustainable for the future. Also, optimizing an aging system has its limits. By designing a whole new concept, a steady ground will be laid and it shall be sustainable for the coming century's technology. The new concept will be called ”C.C.D.D.”, Computer Controlled Direct Descent, and will have a lot of goals and expectations to fulfill. As hinted in the name, the new concept is built on the idea that a computer will be controlling the whole approach, and therefore the "Human factor" will more or less be eliminated. Although the main purpose of a new approach system is to decrease the negative environmental impact, by decreasing the fuel consumption during the approach. The new concept will also decrease the noise an aircraft makes during the descent and increase the possibility for a greater traffic flow in the airport’s airspace. The end result will be a "win-win" for everyone involved. An environmentally friendly aircraft approach is necessary for a sustainable future in aviation. C.C.D.D. is a system that will pay for itself with time, because of the decreased fuel consumption for airliners. The system also has the ability to be expanded to computer control departing aircrafts, due to the systems highly computerized structure and integration with airplanes autopilot.

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  • 2.
    Ahlén, Kritsoffer
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Rosén, Malin
    Mälardalen University, School of Innovation, Design and Engineering.
    Simulering som konstruktionsstöd2013Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
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    Simulering som konstruktionssöd
  • 3.
    Ahmad, Mustafa
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Boukli, Tarék
    Mälardalen University, School of Innovation, Design and Engineering.
    Continuing Airworthiness Management Exposition: For Priority Aero Maintenance2012Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The economic crisis has affected the airline industry as much as it has affected all other industries in the world. The small airlines and maintenance organisations must find new opportunities and options in order to survive the harsh crisis. Priority Aero Maintenance is now an approved maintenance organisation performing maintenance on aircrafts, engines and components. The company sees economic gains in the future by becoming an approved organisation that follows the European Aviation Safety Agency guidelines (EASA) and meets the requirements outlined in the rules of Part-M.

    In order for the company to become an approved organization, responsible for continuing airworthiness of aircraft, a handbook should be presented to the local authority. This handbook describes the company’s responsibility for the continuing airworthiness in order for the authorities to get an insight into the company and its work.

    This thesis resulted in a draft of CAME (Continuing Airworthiness Management Exposition) and this draft has been approved by Priority Aero Maintenance.

    The CAME will in the future be used by the company as a basis for developing a more detailed manual to be presented to and approved by the Swedish Aviation Authority (Transportstyrelsen).

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  • 4.
    Al, Goran
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Boge, Kasper
    Mälardalen University, School of Innovation, Design and Engineering.
    Metod för att säkra innehållet i Scania lastbilars underhållsprogram: Tillämpning av MSG-3 processen från flygindustrin2012Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
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    Rapport - Scania
  • 5.
    Al Hamrani, Emad
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Al-Dulaimi, Anmar
    Mälardalen University, School of Innovation, Design and Engineering.
    Framtida installationskrav på Electronic Flight Bags (EFB): Med hänsyn till litiumbatterier2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This degree project studies the future regulations for the installation of electronic flight bags (EFB) with focus on the hardware and its safety implications in which the task was given by Bromma Air Maintenance (BAM). The aim is to ease the operator to handle issues dealing with EFB; such as lithium battery fire in the cockpit, placement of EFB in the cockpit, etc. This also addresses flight safety, flight controls, emergency evacuation and solutions in dealing with such issues. Flight safely is a vital factor to be considered since it jeopardizes lives. As recent reports indicate an increase in lithium battery powered devices incidents on aircrafts, this paves the way to find new solutions and procedures to mitigate them. By studying the current regulations, Acceptable Means of Compliance (AMC), Advisory Circular (AC) regarding the usage/installation of EFB and future regulation draft (NPA) this study analyzed the changes, which indicated that there were not many significant changes made to the future regulation (new AMC). Although many chapter of the current AMC have been removed and introduced into a new section under AMC & GM (Guidance Material). Different placement of the EFB in cockpit has also been studied in this degree project, which has shown that depending on the placement choice of the aircraft operator there are advantages and disadvantages. This follows by studying the lithium (Li-ion) batteries: technology, mitigation of fire and procedures for lithium battery fire while also studying the recent incidents regarding lithium batteries fire and explosion in commercial and cargo flights. The solutions consist of using the latest technology to propose a new approach to charge the batteries, and store the burning batteries as well. This lead to a smart inductive charger and a smart fire contamination bag to be integrated into the procedures.

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    Framtida installationskrav på EFB
  • 6.
    Alfredsson, Ammar
    Mälardalen University, School of Innovation, Design and Engineering.
    Utvärdering av förebyggande underhållsstrategi för elektriska flygplan2023Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis focuses on the topic of preventive maintenance for electric aircraft and aims to examine its significance and implementation within the aviation industry. Electric aircraft have become increasingly popular as a sustainable alternative to conventional aircraft, making it crucial to develop effective maintenance strategies to ensure their reliability and performance.

    To achieve this objective, a comprehensive literature review of existing research and practices in the field of preventive maintenance for electric aircraft is conducted. The study identifies the key components and systems in an electric aircraft that require regular monitoring and maintenance, such as electric motors, batteries, power converters, and control systems.

    By analyzing the benefits of preventive maintenance, such as reduced downtime, increased component lifespan, and decreased maintenance costs, various methods, and techniques for implementing preventive maintenance for electric aircraft are presented. This includes the use of condition monitoring systems, sensors, and data-driven analysis to monitor and predict the health of components and anticipate any faults or deviations in advance.

    To explore the challenges of preventive maintenance for electric aircraft, aspects such as data management, cooling, and electromagnetic compatibility are also discussed. Furthermore, the need for training and skill development for maintenance personnel to effectively carry out preventive maintenance activities for electric aircraft is explored.

    By compiling and analyzing the available information, this thesis provides a comprehensive overview of preventive maintenance for electric aircraft and its significance in ensuring reliability, performance, and sustainability within the aviation industry. The findings can be valuable to airlines, maintenance organizations, and researchers interested in implementing effective maintenance strategies for electric aircraft and contributing to the continued development of sustainable aviation.

    The literature review showed that the use of preventive maintenance strategy for electric aircraft is well-founded and supported by research and experiences from various industries. The implementation of IoT and fault diagnostic techniques can enhance the maintenance process and increase the reliability of electric aircraft by identifying and addressing potential faults at an early stage. These findings provide valuable insights and guidelines for the aviation industry in developing and optimizing their maintenance strategies for electric aircraft.

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  • 7.
    Amin, Rebin
    Mälardalen University, School of Innovation, Design and Engineering.
    Tool for Risk Evaluation2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
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  • 8.
    Amro, Adib
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Öberg Sjöstrand, Billy
    För- och nackdelar med att förlänga/förkorta flygets underhållsintervaller2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Abstract

    Aircraft maintenance within the aviation industry is an essential part as the purpose is to maintain the aircrafts built-in security and reliability levels. Aircraft require approved and straightforward maintenance to ensure safe operation and airworthiness. The maintenance program's intention is to ensure that a function operates properly despite an uncertain environment. During flights, aircraft are exposed to a large number of loads, which causes components and parts to be affected negatively. Because of this, a maintenance program is presented, the program tries to constantly detect and correct any potential errors before a functional error occurs.

    This degree project is about finding out about the pros and cons of extending or shortening the maintenance interval within the aircraft maintenance program. In addition, the purpose is to draw conclusions about how airline, aircraft turbine performance and age are related to extension or shortening of this maintenance interval. The dissertation was written at the Academy of Innovation, Design and Technology at Mälardalens högskola, Västerås.

    The work process was carried out in several steps. The first step was to deepen the knowledge within the field and understand the maintenance program. This was done through literature studies and information gathering on the subject. The second step was to analyze and process the general information and answers from the interview questions. The work included the advantages and disadvantages caused by extension or shortening of maintenance intervals without affecting the reliability that maintenance requirements ensure. 

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  • 9.
    Andersson, Fredrik
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Karlsson, Rikard
    Mälardalen University, School of Innovation, Design and Engineering.
    HIGHLY CRITICAL GRAPHICS GENERATION ON A SYSTEM-ON-CHIP PLATFORM2022Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The critical applications domain stands today at the brink of a great divide. On one side, the deterministic and safe operational prerequisite of the system. On the other, an ever increasing demand for computational power and miniaturization. In some cases, the welfare of people hinge in the balance of these attributes. It is therefore vital that these system undergo strict and rigorous development and testing. Development has evolved a great deal with regards to computational power and miniaturization. So too has the development of deterministic and safely operational systems. However the combination of these two are a complex matter. A light in the dark might be seen in the Commercial Off The Shelf System-on-Chip, which offers great computational power in relation to its volume. This thesis’s objective is to investigate potential fault-detection methods applicable on commercial System-on-Chip. To determine applicability, multiple implementations have been made and tested. Results from which suggest that fault detection methods implemented on field programmable gate array are highly effective. However, not all worst case execution time analysis conducted in this thesis are deemed a success. A common-mode analysis is conducted which indicated that functions already present on the System-on-Chip, before implementation, negated the effect of common-cause failures under scrutiny in the analysis. The majority of the data gathered from state of the art, implementations and common-mode analysis conducted, indicate that commercial off the shelf multi-processor System-on-Chip platforms have great potential in safety critical systems. 

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  • 10.
    Andersson, Magnus
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Eriksson, Peter
    Analysis of noise levels, audio frequency and fuel consumption with propellers of type McCauley and MT on BAe Jetstream 322012Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report describes a thesis project conducted at Direktflyg in Borlänge, in early 2012, where the aim was to analyse the difference in noise level, audio frequency and fuel consumption between propellers of the older type McCauley and the newer type MT on the aircraft type BAe Jetstream 32. To perform the analysis, the authors reviewed current procedures regarding noise certification from air safety agencies to be able to identify suitable methods for the noise level and audio frequency measurements. The results of the conducted noise level measurements show a general lower noise level throughout the cabin and a significant reduction in noise level behind row 2 when using the MT propeller compared to the McCauley type. In practice this means a lower perceived noise level for most passengers at an average passenger load factor. The frequency measurements show that the MT propeller generates audio frequencies which are perceived as lower in noise levels and are therefore more comfortable for passengers. The fuel consumption was also slightly lower when using the MT propeller compared to the McCauley type over the assigned time period and the determined limiting parameters.

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  • 11.
    Andersson, Staffan
    Mälardalen University, School of Innovation, Design and Engineering.
    Verifieringsinformation: En kvalitativ studie2012Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report deals with how an optimal degree of verification information in a contract shall be attained. While writing contracts there are a limited level of information at hand. Customer requirements are available but the system design is not established. Radar systems are very complex products that lead to many years from contract to final delivery. Meanwhile new technologies are developed and this might lead to redesign. Thus, acceptance tests will be affected and discussions might occur between manufacturer and costumer.

    Discussions might be due to a low level of information at contract level, which might lead to different visions between manufacturer and costumer. On the contrary, too much information causes problems if incorrect information has emerged and if there is a change in design discussions will arise. 

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    Verifieringsinformation
  • 12.
    Andreasson, Victor
    Mälardalen University, School of Innovation, Design and Engineering.
    Regionala flygplatsens fortlevnad: Teknik och Taktik för framgång2023Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The Swedish regional airports outside state ownership and operation shows annual losses. This thesis examines whether technical or tactical measures can improve the economic situation. A current state presentation of a small number of airports is given where their operations in the form of service, flight movements and restrictions are presented. Based on the airport’s different areas, a literature review of new technology and prevailing findings for airports is presented and then reviewed. In several cases, the findings are commented on by people with insight into aviation and airport operations. Airports financial benefits from remote air traffic control are currently assessed as small, except for those with high costs for a traditional tower. Approach aids in the form of Ground-Based Augmentation System Landing System with lower maintenance costs are depending on implementation by other airports and airlines. The airports have great potential to attract customers by working with a customer offer in the form of good self-service, public transport, parking as well as a terminal without queues. Own energy production in the form of solar cells fits well into the airport's operations in combination with, for example, future local hydrogen production. Preventive maintenance and autonomous solutions can save money and simplify work.

  • 13.
    Aslanidou, Ioanna
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Zaccaria, Valentina
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Rahman, Moksadur
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Oostveen, Mark
    Micro Turbine Technology bv, Eindhoven, Netherlands.
    Olsson, Tomas
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems. RISE SICS, Västerås, Sweden.
    Kyprianidis, Konstantinos
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Towards an Integrated Approach for Micro Gas Turbine Fleet Monitoring, Control and Diagnostics2018Conference paper (Refereed)
    Abstract [en]

    Real-time engine condition monitoring and fault diagnostics results in reduced operating and maintenance costs and increased component and engine life. Prediction of faults can change the maintenance model of a system from a fixed maintenance interval to a condition based maintenance interval, further decreasing the total cost of ownership of a system. Technologies developed for engine health monitoring and advanced diagnostic capabilities are generally developed for larger gas turbines, and generally focus on a single system; no solutions are publicly available for engine fleets. This paper presents a concept for fleet monitoring finely tuned to the specific needs of micro gas turbines. The proposed framework includes a physics-based model and a data-driven model with machine learning capabilities for predicting system behaviour, combined with a diagnostic tool for anomaly detection and classification. The integrated system will develop advanced diagnostics and condition monitoring for gas turbines with a power output under 100 kW.

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  • 14.
    Baheta, Aklilu
    et al.
    Universiti Teknologi PETRONAS, Seri Iskandar Perak, Malaysia.
    L. K., Peng
    Universiti Teknologi PETRONAS, Seri Iskandar Perak, Malaysia.
    Suleiman, Shaharin
    Universiti Teknologi PETRONAS, Seri Iskandar Perak, Malaysia.
    Fentaye, Amare Desalegn
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. Universiti Teknologi PETRONAS, Seri Iskandar Perak, Malaysia.
    CFD Analysis of Fouling Effects on Aerodynamics Performance of Turbine Blades2018In: Rotating Machineries:: Aspects of Operation and Maintenanc, Springer, 2018, p. 73-84Chapter in book (Refereed)
    Abstract [en]

    Fouling on gas turbine blades is detrimental to process operation as it may, over a period of time, reduce the blade efficiency and consequently the turbine’s efficiency. With the limitation of today’s technology, experimental study or real-life observation of fouling in a gas turbine is beyond imagination of maintenance engineers. Hence, the effect of fouling cannot be fully quantified for the engineers to come out with mitigation or intervention plans. Nevertheless, computational fluid dynamics (CFD) may provide a good simulation to understand the phenomena. In this chapter, recent effort involving CFD study on the influence of fouling on gas turbine performance is presented. Firstly, the nature of fouling on the gas turbine and the general consequences are discussed. This is followed by an elaboration on how CFD study has been conducted by the authors. Finally, the findings from the study are discussed.

  • 15.
    Barake, Mohammed
    Mälardalen University, School of Innovation, Design and Engineering.
    PW120 Motorprestanda, matchning av motorn, samt mätverktyg för HPT, LPT och PT blad2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
  • 16.
    Ben Sassi, Amin
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Maneekum, Iddaris
    Optimering av B737NG underhållsprogram ur ett tekniskt åtkomstperspektiv2015Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Every airlines maintenance programme is based on the maintenance task thresholds and Repeat Intervals. TUIfly Nordic’s technical department has experienced that some or no consideration has been given to the various maintenance task intervals in relation to the area of the aircraft and the access requirements for performing a maintenance task. Accordingly, we have been assigned by TUIfly Nordic to investigate whether an optimization of the maintenance programme for the B737NG fleet is possible, by taking the area and access requirements of the plane into account. As a direct result of how current maintenance programme is constructed, tasks conducted on a specific area of the aircraft are not coordinated, which means that opening/removal of panels/doors are made too often, therefore costing a lot of time and money.

    The purpose of the thesis was to identify possible adjustments in the intervals to coordinate the maintenance tasks by area and access requirements. TUIfly Nordic's concerns regarding their maintenance programme have been studied through data collection and analysis from various literature studies, especially from the company's and the manufacturer's manuals. A compilation of 41 maintenance tasks in seven areas has been presented where de-escalation in threshold is an option to schedule maintenance tasks that occur in the same area and access requirements. The result that is presented is only a concept and can therefore not be used directly into the maintenance programme, without an evaluation made by TUIfly Nordic’s technical department. The final outcome of this thesis is a recommendation on how to best optimize a maintenance programme for B737NG, in the matter of taking the area and access requirements of the plane into account, which was the objective and desired outcome of the work.  

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  • 17.
    Benini, E.
    University of Padova, Italy.
    Advances in Gas Turbine Technology2011Collection (editor) (Refereed)
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  • 18.
    Berg, Kim
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Peerzadah, Wais
    Mälardalen University, School of Innovation, Design and Engineering.
    Implementering av MSG-3 process på traktionsmotor LJE108-12012Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    For the operator, it is important that the trains are available when they are scheduled to be used. In order to keep trains running they need to be maintained. Unscheduled stoppages due to breakdowns and errors cost both money and time for the operator. Unplanned downtime can also affect other trains, by operating the track due to stop.

    This thesis is aimed to improve the preventive maintenance of traction motor like MSG-3 analysis for aircraft.. The goal is to ensure the right content in the maintenance program to prevent unplanned downtime. The purpose of the MSG-3 methodology, besides obtaining all scheduled maintenance tasks and intervals as shall be to maintain and restore the part's built-in reliability levels, to obtain information necessary for design improvements where it is found that the design does not measure up.

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  • 19.
    Bergman, Caroline
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Bergman, Tobias
    Mälardalen University, School of Innovation, Design and Engineering.
    Strukturering av jobbkort: -för ökad effektivitet i underhållsplaneringen2015Student paper other, 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis was carried out in co-operation with Airline Support AB. Airline Support AB is in accordance with EASA part145 an approved maintenance organization, that performs maintenance work for airline operators as consultants.

     

    Undertaking a major maintenance mission, Airline Support AB receives an Work order from their client which contains hundreds of unorganized task cards. With limited access to technical means, the TCs is sorted and organized physically according to their expected applicability. The order in which the TCs should be arranged is determined by dividing the TCs equally between the three working teams and between one of the three different aircraft fuselage zones.

     

    The physical organization of the large amount of TCs is time-consuming and the process have to be redone every time a new maintenance commitment have been made. This creates poor conditions to follow-up the progress during the maintenance work and to be able to give reliable information to their clients.

     

    The main purpose of this thesis work was to get an insight in how the maintenance work is being executed and handled in an approved Part-145 organization in reality. The goal was also to find a specific structure for the TCs and create a dynamic system that could automatically organize some parts of the maintenance planning process.

     

    The thesis was carried out while consulting Airline Support AB, according to their requests and organizational needs.  It was established that the TCs should be divided in terms of calculated man-hours for each card and according to the three aircraft fuselage zones. After comparing different software and their possibilities, Excel was chosen to be the most suitable option for creating the type of system desired.

     

    A planning tool was then created according to agreed functions and desires, using Visual Basics to program the software.  The planning tool is the essential result from working on this thesis and concludes the result of all the project phases.

     

    The planning tool created is not a complete product. It takes a lot more work to get the man-hours performing the maintenance tasks calculated more precise. A more precis calculation would make the system seem closer to the reality. Due to a lot of time and effort spent during the project on testing and implementation, there is a high probability for the developed tool to live up to the expectations, and forfill the main goal to save resources and optimize the maintenance work.

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  • 20.
    Bjenning, Jonas
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Algotsson, Simon
    Mälardalen University, School of Innovation, Design and Engineering.
    Underhållssystem Gripen C/D2015Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Abstract

    Saab wanted to review how todays maintenance manuals are produced and maintained for GripenC/D, mainly by merging the maintenance manual and the configuration list. The reason forthis was to simplify the interpretation and increase production flow while producing the manuals.The challenge this thesis had to face was to structure and sort which information were relevantand needed to be featured while also adding new information which is not presented in todaysdocuments. The production tool used today is complex and hard to use which lead to Saab wantingto review the possibility to use a database based production tool instead. This thesis focuses onmerging the two documents into a more comprehensible layout as well as doing a preparation foran upcoming database.Through careful studies in Human Factors and how to easily present information and reducing therisks of missunderstandings an understanding was given in how a merged layout would look. Studiesin database modelling was necessary to get a better understanding in how databases are structured.This thesis resulted in a merged document where the maintenance manual and configuration listis presented in a landscape view on the same page. This simplified the interpretation a lot whilehandling the manual. This thesis also resulted in an explanation of how the documents relate toeach other which could be used to build the database in the future. This would, if implemented,increase production flow and maintainability for the maintenance manual.

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  • 21.
    Broman, John
    Mälardalen University, School of Innovation, Design and Engineering.
    Estimering av tidsåtgång vid planerat underhåll av Boeing 737-8002014Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The Swedish charter airline TUIfly Nordic AB has experienced problems determining the correct number of man-hours required to perform planned maintenance activities on the aircraft type Boeing 737-800. The problems have concerned the man-hour estimates for task cards in the aircraft type’s maintenance program and the man-hour estimates for the opening and closing of access panels. To address this problem, this thesis project has developed methods for modifying the man-hour estimates included in TUIfly Nordic’s Boeing 737-800 maintenance program related to task cards and access panels. A method for the determination of the time required to rectify findings detected when performing task cards has also been developed.

    The developed methods have been used to calculate new man-hour estimates in Microsoft Excel. The calculated man-hour estimates for access panels are the man-hour estimates provided by the aircraft manufacturer Boeing multiplied by a factor of two. For most task cards, the calculated man-hour estimates are the man-hour estimates provided by Boeing multiplied by a factor of four, plus an estimation of the man-hours required to rectify findings. It has been concluded that these new man-hour estimates represent an improvement of the airline’s man-hour estimates for access panels and task cards.

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    Estimering av tidsåtgång vid planerat underhåll av Boeing 737-800
  • 22.
    Bruhn, Fredrik
    et al.
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems. Unibap AB, Sweden.
    Alice, Anlind
    Unibap AB, Sweden.
    Nunes, Miguel
    Hawaii Space Flight Laboratory, University of Hawaii at Manoa, Honolulu, HI, USA.
    Amber, Imai-Hong
    Hawaii Space Flight Laboratory, University of Hawaii at Manoa, Honolulu, HI, USA.
    Wood, Mark
    University of Hawaii at Manoa, USA.
    Wright, Robert
    University of Hawaii at Manoa.
    Lucey, Paul
    University of Hawaii at Manoa, USA.
    Flynn, Luke
    University of Hawaii at Manoa, USA.
    HYTI mission: Raw thermal instrument on-orbit data processing with SpaceCloud2022Conference paper (Refereed)
    Abstract [en]

    The HyTI (Hyperspectral Thermal Imager) mission, funded by NASA’s Earth Science TechnologyOffice InVEST (In-Space Validation of Earth Science Technologies) program, is the first US science satellite to leverage heterogenous SpaceCloud hardware with CPU and GPU acceleration. The mission will demonstrate how high spectral and spatial long-wave infrared image data can be acquired from a 6U CubeSat platform and perform advanced on-orbit real-time data processing and creating L1 and L2 products. The mission will use a spatially modulated interferometric imaging technique to produce spectro-radiometrically calibrated image cubes, with 25 channels between 8-10.7 μm, at 13cm-1resolution) at a ground sample distance of ~60 m. The small form factor of HyTI is made possible via a no-moving-parts Fabry-Perot interferometer and JPL’s cryogenically cooled HOTBIRD FPA technology. The value of HyTI to Earth scientists will be demonstrated via on-board processing of the raw instrument data to generate L1 and L2 products, with a focus on rapid deliveryof data regarding volcanic degassing, land surface temperature, and precision agriculture metrics.This presentation will provide an overview of the HyTI measurement approach, the onboard data reduction approach, and the spacecraft design. We will also update HyTI integration, testing, andfuture mission concepts based on the SpaceCloud Framework containerization of mission management and data applications.

  • 23.
    Carmegren, Emil
    Mälardalen University, School of Innovation, Design and Engineering.
    Markov Chains as a Real-time System Monitoring Service: Numerical Repair Rate Optimization (RRO)2022Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The expansion and increased complexity of technology is undoubtedly consistent and one can intuitively suppose that this trajectory will not deviate from this course in the years to come. On a continuous basis, concepts that started of as some hypothetical or abstract notions without practical relevance gets transferred to the modern state of our current technology. During these times, where a subset of our technology has the responsibility of handling the safety of our being, research within dependability theory must keep up the pace with technology. One cannot emphasize enough the importance of ensuring the validity of system dependability attributes prior and posterior to development. With the objective of aggregating findings to the research field and potentially derive new propositions this paper assesses the stochastic modeling concepts used within dependability theory. In particular, discrete-time-and continuous-time-Markov chains are outlined in detail, searching for possibilities to extend these processes in the context of real-time system monitoring. As an outcome, numerical 'repair rate optimization' (RRO) through CTMC uniformization is introduced. A technique which deduces a proposed allocation of repair rate adjustment based on the models parametric sensitivities (gradient ascent). The theoretical aspects are verified by development of an algorithm in Matlab that utilizes the above. Additionally, an approach of combining dependability attributes into a unified measure is proposed. Where the (bounded) transient probabilities are regarded as vectors in the L2(R, B(R), λ) Hilbert Space. For which a normalized dependability norm can be obtained by using the induced norm and triangle inequality. This serves as a metric to compare distinct architectures in terms of several, quantitative attributes. The results imply that under the hypothesis that the system/company can adapt to an increased demand on maintenance periodicity, reliability/availability can be significantly improved. Mitigating risk of failure while optimally preserving resources in terms of e.g. core capacity, maintenance personnel, budget and/or required redundancy while conditioning on the actual system behaviour. 

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  • 24.
    Celis, Cesar
    et al.
    Cranfield University, UK.
    Mohseni, Martina
    Cranfield University, UK.
    Kyprianidis, Konstantinos G.
    Mälardalen University, School of Business, Society and Engineering. Cranfield University, UK.
    Sethi, Vishal
    Cranfield University, UK.
    Ogaji, Stephen O. T.
    Cranfield University, UK.
    Haslam, Antony
    Cranfield University, UK.
    Pilidis, Pericles
    Cranfield University, UK.
    Multidisciplinary Design Optimization of Aero Engines: Environmental Performance-Based Methodology2008In: SYMKOM’08 Proceedings. CIEPLNE MASZYNY PRZEPLYWOWE. TURBOMACHINERY. No.133, 2008Conference paper (Refereed)
    Abstract [en]

    A methodology and tool that allows evaluating and quantifying aero engines design trade-offs originated as a consequence of addressing conflicting objectives such as low environmental impact and low operating costs is presented, and applied to a general case study to assess the feasibility of using new highly efficient engine configurations: intercooled- recuperated (ICR) engines. The case study results show that according to the ICR systems performance (heat exchangers effectiveness, pressure losses, and weight penalty) they could find usage in practical applications.

  • 25.
    Chimbani, John
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Petterson, Robin
    Mälardalen University, School of Innovation, Design and Engineering.
    Marknadsundersökning: Lämpliga flygplan med avseende på start- och landningssträckor för Bunge flygfält2013Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
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  • 26.
    Colmenares, Fernando
    et al.
    Cranfield University, Cranfield, Bedfordshire, England, UK.
    Kyprianidis, Konstantinos
    Cranfield University, Cranfield, Bedfordshire, England, UK.
    Gómez, Josué
    Cranfield University, Cranfield, Bedfordshire, England, UK.
    Ogaji, Stephen
    Cranfield University, Cranfield, Bedfordshire, England, UK.
    Pilidis, Pericles
    Cranfield University, Cranfield, Bedfordshire, England, UK.
    Latorre, Sergio
    Universidad de Antioquia, Medellín, Colombia.
    Future Aero-Engines’ Optimisation for Minimal Fuel Burn2008In: ASME Turbo Expo 2008: Power for Land, Sea, and AirVolume 2: Controls, Diagnostics and Instrumentation; Cycle Innovations; Electric PowerBerlin, Germany, June 9–13, 2008, 2008, p. 411-416Conference paper (Refereed)
    Abstract [en]

    While aircraft environmental performance has been important since the beginnings of commercial aviation, continuously increasing passenger traffic and a rise in public awareness have made aircraft noise and emissions two of the most pressing issues hampering commercial aviation growth today. The air transportation for the new millennium will require revolutionary solutions to meeting public demand for improving safety, reliability, environmental compatibility, and affordability. The objective of this research is to assess the trade-off between operating costs and environmental requirements of the future aero engines for short range commercial aircrafts. This involves optimising the engines’ design point to minimise the block fuel and evaluating the economic and environmental impact. A high by-pass ratio turbofan engine with performance characteristics and technology from the year 2000 was set up as a baseline and compared to very high by-pass ratio turbofans. The results present a great potential benefit of the geared turbofan compared to high BPR one (baseline) to reduce cruise CO2 emissions and noise; however this may involve NOx penalties, that is an increase of 5.1% in comparison to the baseline. The CRTF engine seems to be, at least according to the simulations, a very promising solution in terms of environmental and economical performance. This is one on the series of work that would be carried out on the cycles being assessed in this paper (feasibility study). Further work on the specific technical issues — such as: technological implications — would be published when completed.

  • 27.
    Cunha, Henrique E.
    et al.
    Chalmers University of Technology.
    Kyprianidis, Konstantinos G.
    Chalmers University of Technology.
    Investigation of the Potential of Gas Turbines for Vehicular Applications2012In: Proc. ASME. 44694; Volume 3: Cycle Innovations; Education; Electric Power; Fans and Blowers; Industrial and Cogeneration. GT2012-68402, 2012, p. 51-64Conference paper (Refereed)
    Abstract [en]

    Nowadays, the reduction of fuel consumption and pollutant emissions has become a top priority for society and economy. In the past decades, some of the environmental advantages of the gas turbine (such as inherently low CO and unburned HC) have led some car manufacturers to evaluate the potential of this type of engine as prime mover. This paper suggests a strategy to assess the fuel consumption of gas turbines applied in road vehicles. Based on a quasistatic approach, a model was created that can simulate road vehicles powered by gas turbines, and thereafter a comparison was established with reciprocating engines. Within this study, material and turbomachinery technology developments that have taken place in micro gas turbines since the 1960’s have been considered. A 30% efficiency improvement target has been identified with respect to making the gas turbine fuel competitive to a diesel engine powering an SUV. It is the authors’ view that several technologies that could mature sufficiently within the next 10–15 years exist, such as uncooled ceramic turbines. Such technologies could help bridge the fuel efficiency gap in micro gas turbines and make them commercially competitive in the future for low-emissions vehicular applications. Furthermore, the system developed also allows the simulation of hybrid configurations using gas turbines as range extenders, a solution that some car manufacturers consider to be the most promising in the coming years.

  • 28.
    De-Millo, Maxim
    Mälardalen University, School of Innovation, Design and Engineering.
    Analys av TCAS trafikdisplay och förbättring av pilotens förståelse för systemet.2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Detta arbete berör den grafiska presentationen av antikollisionssystemet TCAS. TCAS är ett oberoende system som används för att piloten ska ha en bra översyn om trafiksituationen runt om sitt egna flygplan och vid ett farligt närmande få manöverrådgivningar för att undvika kollision. För piloten presenteras TCAS på en trafikdisplay som ofta är integrerad i någon annan display såsom navigationsdisplayen. Vid manöverrådgivning får man rådgivningar på en RAdisplay som ofta är integrerad i PFD.  Syftet med detta arbete är att se om det går att förbättra den grafiska presentationen som piloten får, då det har visat sig att förståelsen för systemet ibland är bristande och vid hög trafikdensitet kan det bli rätt rörigt på trafikdisplayen. Detta är viktigt då piloten måste ha en bra uppfattning om trafiksituationen och kunna vara beredd på att göra en undanmanöver. Det är även viktigt att systemet är simpelt samtidigt som den ger all nödvändig information för att piloten ska vara medveten om trafiksituationen.   Jag har i detta arbete utvecklat nya symboler genom att titta på riktlinjer för symboldesign. Symbolerna utvecklades med hänsyn till mänskliga faktorer och hur människan reagerar på olika faktorer i symbolen, som till exempel färg, uppmärksamhetsfaktorer och form. Det befintliga systemet testades i en flygsimulator. Detta gav en bra praktisk bild av hur systemet ser ut idag, och även en ide om hur jag ska utveckla de nya symbolerna.    En intervju gjordes bland 6 kommersiella piloter, och utifrån deras feedback fick jag en förståelse för vad de ville ha för information på trafikdisplayen och vad de tyckte om det system jag utvecklat. Modifieringar gjordes och som resultat fick jag en simpel, men ändå informativ symboluppsättning.  Den nya presentationen gav i överlag ett positivt intryck, trots att de piloter som blev intervjuade sa att de skulle kunna använda den nya designen, var de nöjda med det befintliga systemet. De tyckte dock att den nya designen kunde vara bra vid utbildning.

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  • 29.
    Edkvist, Markus
    Mälardalen University, School of Innovation, Design and Engineering.
    Genomgång av A-checkupplägg till Dash 8 Q4002015Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In this report I summarize the thesis, which is about to check what will happen if you decide to increase the interval between the a-checks, carried out on the Norwegian airline Widerøe. They want to know if an increase in time between the checks can give them an opportunity of increasing their aircraft fleet. In the current situation Widerøe has 11  Dash 8 Q400 and can consider a possible increase of 3 planes. This would be done without the need to increase accessibility of the hangars and increase in staff.

    What determines how often a check is performed is the maintenance tasks which has the shortest maintenance interval. On the Dash 8 the shortest interval is 600 flight hours. Therefore, a check must be performed once every 600 flight hour.

    But since there is so many maintenance tasks that will be performed at every check point, Widerøe have decided to divide their checks. They do this by dividing every check-package into four smaller packages. With this layout they get a breakdown of 150 flight hours instead of 600, and so you get less time between maintenance and fewer maintenance tasks at each occasion.

    My work started by developing a new checking package of 600 flight hours of interval. I did this by merging the existing check-package of 150 flight hour intervals into a checking package with 600-hour intervals. After that, it took considerable amount of work to define the differences between the various check packages. I started to count on whether you saved or not saved time by lengthening the interval. After that I optimized the number of technicians needed at each check and then calculated the total time required for each check.

    In the end I came up with two possible solutions. The first option is to use my check program with 600 flight hours of interval, and then increase the fleet with two aircrafts. The second option is to use a checking program with 300 flight hours of interval and then increase the fleet with one aircraft.

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  • 30.
    Edlund, Per
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Mami, Nihel
    Mälardalen University, School of Innovation, Design and Engineering.
    Elektriskt Framdrivningssystem för Högpresterande Ultralätt Flygplan2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    BlackWing Sweden AB manufactures ultralight aircraft made from carbon fibre composite. The company's vision is to produce an aircraft that can be completely powered by electricity with the same performance as the aircraft powered by fossil fuels. To operate the BlackWing aircraft using electricity it will need a battery pack, electronic controls and an electric driveline. Therefore, this thesis has been devoted primarily to study which electric engine and battery cells that would be most suitable for the BlackWing aircraft. The result was produced by calculations of the battery cells and electric driveline by using collected information about driveline and battery performance. To get a more objective and systematic results, a Pugh matrix was used to easily determine the most suitable battery cell. The results of this work showed that in the current situation, the battery Envia High Energy Drone Cell Pouch (ENV35011-CRC) and Siemens engine DYNADYN® 85 are the most suitable for the BlackWing aircraft.

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    Elektriskt Framdrivningssytem för Högpresterande Ultralätt Flygplan
  • 31.
    Eggen, Iver Bergh
    Mälardalen University, School of Innovation, Design and Engineering.
    Nitrogen servicing, NH902013Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The NH90 multi-role helicopter is a new weapon system that is now integrating into the Norwegian air-force and marine. It is meant to be used on frigates and on coastguard ships. The Norwegian Defence Logistics Organisation (NDLO) quickly realized that they didn't have the necessary capability to service the helicopter with nitrogen on board ships. In this project I have come up with a specification/functional description of a system that can solve this problem. To achieve the high pressures required of the different systems on the NH90 a gas booster needs to be used and the resulting system is a suggestion on how a booster system can be used safely. To get to this result I have documented different military and civilian requirements, described the different systems and why they need to be serviced with nitrogen, described how the different items need to be serviced and how they service it today.  The resulting system is the solution that I have found that complies with the most requirements, is safe and cost effective. I have also done a risk assessment and an economical assessment of the system

  • 32.
    Eklund, John
    et al.
    Mälardalen University, School of Innovation, Design and Engineering, Innovation and Product Realisation.
    El-Khouri, Michel
    Mälardalen University, School of Innovation, Design and Engineering, Innovation and Product Realisation.
    Beräkning av hissgejder2015Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    En central komponent i ett hissystem är gejder. Dessa fungerar som ledskenor och styr hissen i dess färdriktning. De ser till att hissen hålls på plats och tar därför upp alla de krafter som av olika anledningar genereras av obalans i hissen. Om dessa krafter blir för stora uppkommer skador som kan leda till olyckor och det är därför viktigt att dimensionera gejderna rätt.

    Företaget Kone AB har genom tiderna utvecklat flera olika beräkningsverktyg för att teoretiskt bestämma hur stora påfrestningar en specifik hiss kan utgöra på dess gejder. Dessa verktyg har framförallt fokuserat på installation av nya hissar och dagens förutsättningar. Med tiden har föreskrifter, normer och standarder förändrats. Nya gränsvärden och regler har medfört att nya verktyg utvecklats för att kunna anpassas efter detta. Beroende på vilken del av en hiss som moderniseras, gäller fortfarande de föreskrifter och riktvärden som var gällande då hissen uppfördes. I samband med nyutvecklingar av beräkningsverktyg har man släppt supporten av gamla versioner och många av de äldre programmen har idag kompabilitetsproblem med dagens plattformar. Man har heller inte behållit någon möjlighet till att räkna efter gamla regler och riktvärden. Detta har medfört glapp i tillgängligheten av beräkningsverktyg anpassade för moderniseringar och har lett till att mycket tid har spenderats åt att genomföra dessa beräkningar med papper och penna.

    Arbetet har genererat ett nytt beräkningsverktyg skapat i Microsoft Excel och Visual Basic for Applications med fokus på att lämna så mycket som möjligt konfigurerbart. På detta sätt kan man anpassa alla nödvändiga parametrar och riktvärden efter de föreskrifter som gällde då hissen var uppförd. Plattformen valdes då det finns gott om allmän kännedom om denna inom företaget för att underlätta framtida vidareutveckling och inte få problem med otillgänglig källkod.

    Ett sidospår ledde in på en utredning gällande materialegenskaper för gejder tillverkade på tidigt 1900-tal. Detta ledde till för få resultat för att kunna dra några slutsatser och någon gemensam standard kunde inte finnas.

    För framtida vidareutveckling av verktyget rekommenderas grafiska illustrationer av resultatdelen samt implementation av fler områden som kan automatiseras inom avdelningen.

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  • 33.
    Eliasson, Carl
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Hedberg, Alexander
    Mälardalen University, School of Innovation, Design and Engineering.
    VR-flygsimulatorer, för ökad upplevelse och som läroverktyg i flygutbildningar2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Virtual reality (VR) is a rising phenomenon that has skyrocket in popularity the past year. VR is often referred to as a computer generated virtual environment the user gets immersed in. The VR environment is experienced through different types of sensory stimuli.The purpose of this thesis is to examine how realistic a commercially available VR flight simulator is being perceived by real pilots as well as examine if VR technology could be a viable educational tool for flight schools. The motivations of this thesis are the facts that the VR-technology has advanced in a quick phase. Many of the past difficulties with implementing VR technology have been addressed with new fully integrated head mounted displays therefor capability issues are no longer a big problem. Because of the simplicity of new VR-systems it’s a good time to investigate VR uses and how it compares to traditional flight simulator techniques.The method used for the thesis started with collecting information about VR technology and traditional flight simulators. With that information a survey consisting of two parts was created. The first part was an experiment with a VR flight simulator, and the second part was an interview conducted directly after the experiment. Seven jet fighter pilots participated in the survey.Our results show that a VR flight simulator is perceived as more realistic compared to a traditional flight simulator. It is also shown that VR technology could be a good educational tool if some of the issues that were found are resolved or improved upon.

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  • 34.
    Eriksson, Gabriel
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Andersson, Adam
    Mälardalen University, School of Innovation, Design and Engineering.
    Utformning av målflygplan2013Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Scandicraft AB had an intention to develop a new target drone that could reach Mach 0.5 in a span of altitude from 50 m to 5000 m. Jet engines normally found in model aircraft would be used as propulsion. The aircraft was designed to maintain non-accelerated level flight at the speed of Mach 0.5 at an altitude of 50 m. An analysis revealed that the aerodynamic drag of the aircraft was too large. To lower the drag, the fuel quantity was reduced from 40 kg to 13 kg and the minimum speed was increased.

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    Design_of_Target_Drone
  • 35.
    Fadhil, Aya
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Zawawi, Maya
    Mälardalen University, School of Innovation, Design and Engineering.
    A DEPENDABILITY PERSPECTIVE TO MONITOR EXERCISES USING A MOBILE ECG SENSOR2022Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
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  • 36.
    Fentaye, Amare Desalegn
    et al.
    Department of Mechanical Engineering, Universiti Teknologi Petronas, Tronoh, Malaysia.
    Baheta, Aklilu
    Department of Mechanical Engineering, Universiti Teknologi Petronas, Tronoh, Malaysia.
    Gilani, Syed Ihtsham Ul-Haq
    Department of Mechanical Engineering, Universiti Teknologi Petronas, Tronoh, Malaysia.
    Gas turbine gas-path fault identification usingnested artificial neural networks2018In: Aircraft Engineering, ISSN 0002-2667, Vol. 90, no 6, p. 992-999Article in journal (Refereed)
    Abstract [en]

    Purpose – The purpose of this paper is to present a quantitative fault diagnostic technique for a two-shaft gas turbine engine applications.Design/methodology/approach – Nested artificial neural networks (NANNs) were used to estimate the progressive deterioration of single andmultiple gas-path components in terms of mass flow rate and isentropic efficiency indices. The data required to train and test this method areattained from a thermodynamic model of the engine under steady-state conditions. To evaluate the tolerance of the method against measurementuncertainties, Gaussian noise values were considered.Findings – The test results revealed that this proposed method is capable of quantifying single, double and triple component faults with asufficiently high degree of accuracy. Moreover, the authors confirmed that NANNs have derivable advantages over the single structure-basedmethods available in the public domain, particularly over those designed to perform single and multiple faults together.Practical implications – This method can be used to assess engine’s health status to schedule its maintenance.Originality/value – For complicated gas turbine diagnostic problems, the conventional single artificial neural network (ANN) structure-based faultdiagnostic technique may not be enough to get robust and accurate results. The diagnostic task can rather be better done if it is divided and sharedwith multiple neural network structures. The authors thus used seven decentralized ANN structures to assess seven different component faultscenarios, which enhances the fault identification accuracy significantly.

  • 37.
    Fentaye, Amare Desalegn
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Baheta, Aklilu
    Syed, Gilani
    Gas path fault diagnostics using a hybrid intelligent methodfor industrial gas turbine engines2018In: Journal of the Brazilian Society of Mechanical Sciences and Engineering, ISSN 1678-5878, E-ISSN 1806-3691, Vol. 40, article id 578Article in journal (Refereed)
    Abstract [en]

    There are many challenges against an accurate gas turbine fault diagnostics, such as the nonlinearity of the engine health,the measurement uncertainty, and the occurrence of simultaneous faults. The conventional methods have limitations ineffectively handling these challenges. In this paper, a hybrid intelligent technique is devised by integrating an autoassociativeneural network (AANN), nested machine learning (ML) classifiers, and a multilayer perceptron (MLP). The AANNmodule is used as a data preprocessor to reduce measurement noise and extract the important features for visualisation andfault diagnostics. The features are extracted from the bottleneck layer output values based on the concept of the nonlinearprincipal component analysis (NLPCA). The nested classifier modules are then used in such a manner that fault and no-faultconditions, component and sensor faults, and different component faults are distinguished hierarchically. As part of the classification,evaluation of the fault classification performance of five widely used ML techniques aiming to identify alternativeapproaches is undertaken. In the end, the MLP approximator is utilised to estimate the magnitude of the isolated componentfaults in terms of flow capacity and isentropic efficiency indices. The developed system was implemented to diagnose up tothree simultaneous faults in a two-shaft industrial gas turbine engine. Its robustness towards the measurement uncertaintywas also evaluated based on Gaussian noise corrupted data. The test results show the derivable benefits of integrating twoor more methods in engine diagnostics on the basis of offsetting the weakness of the one with the strength of another.

  • 38.
    Fentaye, Amare Desalegn
    et al.
    Universiti Teknologi PETRONAS, Malaysia.
    Baheta, Aklilu T.
    Universiti Teknologi PETRONAS, Malaysia.
    Gilani, Syed I.
    Universiti Teknologi PETRONAS, Malaysia.
    Kyprianidis, Konstantinos
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    A Review on Gas Turbine Gas-Path Diagnostics: State-of-the-Art Methods, Challenges and Opportunities2019In: Aerospace, E-ISSN 2226-4310, Vol. 6, no 7, article id 83Article, review/survey (Refereed)
    Abstract [en]

    Gas-path diagnostics is an essential part of gas turbine (GT) condition-based maintenance (CBM). There exists extensive literature on GT gas-path diagnostics and a variety of methods have been introduced. The fundamental limitations of the conventional methods such as the inability to deal with the nonlinear engine behavior, measurement uncertainty, simultaneous faults, and the limited number of sensors available remain the driving force for exploring more advanced techniques. This review aims to provide a critical survey of the existing literature produced in the area over the past few decades. In the first section, the issue of GT degradation is addressed, aiming to identify the type of physical faults that degrade a gas turbine performance, which gas-path faults contribute more significantly to the overall performance loss, and which specific components often encounter these faults. A brief overview is then given about the inconsistencies in the literature on gas-path diagnostics followed by a discussion of the various challenges against successful gas-path diagnostics and the major desirable characteristics that an advanced fault diagnostic technique should ideally possess. At this point, the available fault diagnostic methods are thoroughly reviewed, and their strengths and weaknesses summarized. Artificial intelligence (AI) based and hybrid diagnostic methods have received a great deal of attention due to their promising potentials to address the above-mentioned limitations along with providing accurate diagnostic results. Moreover, the available validation techniques that system developers used in the past to evaluate the performance of their proposed diagnostic algorithms are discussed. Finally, concluding remarks and recommendations for further investigations are provided.

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  • 39.
    Fentaye, Amare Desalegn
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. Univ Teknol PETRONAS, Dept Mech Engn, Perak, Malaysia.
    Gilani, Syed
    Univ Teknol PETRONAS, Dept Mech Engn, Tronoh 31750, Perak, Malaysia.
    Baheta, Aklilu
    Univ Teknol PETRONAS, Dept Mech Engn, Tronoh 31750, Perak, Malaysia.
    Gas turbine gas path diagnostics:: A review2016In: MATEC Web of Conferences 74, 00005, 2016, Vol. 74, article id 00005Conference paper (Refereed)
    Abstract [en]

    In this competitive business world one way to increase profitability of a power production unit is to reduce the operation and maintenance expenses. This is possible if the gas turbine availability and reliability is improved using the appropriate maintenance action at the right time. In that case, fault diagnostics is very critical and effective and advanced methods are essential. Gas turbine diagnostics has been studied for the past six decades and several methods are introduced. This paper aims to review and summarise the published literature on gas path diagnostics, giving more emphasis to the recent developments, and identify advantages and limitations of the methods so that beginners in diagnostics can easily be introduced. Towards this end, this paper, identifies various diagnostic methods and point out their pros and cons. Finally, the paper concludes the review along with some recommended future works.

  • 40.
    Fentaye, Amare Desalegn
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. Department of Mechanical Engineering, Universiti Teknologi Petronas, Tronoh, Malaysia.
    Gilani, Syed
    Department of Mechanical Engineering, Universiti Teknologi Petronas, Tronoh, Malaysia.
    Baheta, Aklilu
    Department of Mechanical Engineering, Universiti Teknologi Petronas, Tronoh, Malaysia.
    Yi-Guang, Li
    Department of Aerospace, Transport and Manufacturing, Cranfield University, Cranfield, UK.
    Performance-based fault diagnosis of agas turbine engine using an integratedsupport vector machine and artificialneural network method2019In: Proceedings of the Institution of mechanical engineers. Part A, journal of power and energy, ISSN 0957-6509, E-ISSN 2041-2967, Vol. 233, no 6, p. 786-802Article in journal (Refereed)
    Abstract [en]

    An effective and reliable gas path diagnostic method that could be used to detect, isolate, and identify gas turbinedegradations is crucial in a gas turbine condition-based maintenance. In this paper, we proposed a new combinedtechnique of artificial neural network and support vector machine for a two-shaft industrial gas turbine engine gaspath diagnostics. To this end, an autoassociative neural network is used as a preprocessor to minimize noise and generatenecessary features, a nested support vector machine to classify gas path faults, and a multilayer perceptron to assess themagnitude of the faults. The necessary data to train and test the method are obtained from a performance model of thecase engine under steady-state operating conditions. The test results indicate that the proposed method can diagnoseboth single- and multiple-component faults successfully and shows a clear advantage over some other methods in termsof multiple fault diagnosis. Moreover, 5-8 sets of measurements have been used to assess the prediction accuracy, andonly a 2.3% difference was observed. This result indicates that the proposed method can be used for multiple faultdiagnosis of gas turbines with limited measurements.

  • 41.
    Fentaye, Amare Desalegn
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Kyprianidis, Konstantinos
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    An intelligent data filtering and fault detectionmethod for gas turbine engines2020In: MATEC Web of Conferences 314, 2020, Vol. 314, article id 02007Conference paper (Refereed)
    Abstract [en]

    In a gas turbine fault diagnostics, the removal of measurementnoise and data outliers prior to the fault analysis is very essential. Theconventional filtering methods, particularly the linear ones, are notsufficiently accurate, which might possibly lead to the loss of criticallyimportant features in the fault analysis process. Conversely, the recordedaccuracies obtained from the non-linear filters are promising. Recently, thefocus has been shifted to the artificial neural network (ANN) based nonlinearfilters due to their capability of providing a robust identity map between theinput and output data, which can be efficiently exploited in the process offault diagnosis. This paper aims to present combined auto-associative neuralnetwork (AANN) and K-nearest neighbor (KNN) based noise reduction andfault detection method for a gas turbine engine application. The performanceof the developed method has been evaluated using data obtained from amodel simulation. The test results revealed that the developed hybrid methodis more effective and reliable than the conventional methods for the faultdetection of the gas turbine engine with negligible false alarms and misseddetections.

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    fulltext
  • 42.
    Fentaye, Amare Desalegn
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. Univ Teknol PETRONAS, Dept Mech Engn, Bandar Seri Iskandar, Malaysia.
    Syed, Gilani
    Univ Teknol PETRONAS, Dept Mech Engn, Bandar Seri Iskandar, Malaysia.
    Baheta, Aklilu
    Univ Teknol PETRONAS, Dept Mech Engn, Bandar Seri Iskandar, Malaysia.
    Ahmed, Mojahid
    Univ Teknol PETRONAS, Dept Mech Engn, Bandar Seri Iskandar, Malaysia.
    Two-shaft stationary gas turbine engine gas path diagnostics using fuzzy logic2017In: Journal of Mechanical Science and Technology, Vol. 31, no 11, p. 5593-5602Article in journal (Refereed)
    Abstract [en]

    Our objective was to develop a Fuzzy logic (FL) based industrial two-shaft gas turbine gas path diagnostic method based on gas pathmeasurement deviations. Unlike most of the available FL based diagnostic techniques, the proposed method focused on a quantitativeanalysis of both single and multiple component faults. The data required to demonstrate and verify the method was generated from asimulation program, tuned to represent a GE LM2500 engine running at an existing oil & gas plant, taking into account the two mostcommon engine degradation causes, fouling and erosion. Gaussian noise is superimposed into the data to account measurement uncertainty.Finally, the fault isolation and quantification effectiveness of the proposed method was tested for single, double and triple componentfault scenarios. The test results show that the implanted single, double and triple component fault case patterns are isolated with anaverage success rate of 96 %, 92 % and 89 % and quantified with an average accuracy of 83 %, 80 % and 78.5 %, respectively.

  • 43.
    Ferreira, Klas
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Jeleborg, Douglas
    Mälardalen University, School of Innovation, Design and Engineering.
    Anpassning och optimering av checkprogram för AW1392015Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Presently Sjöfartsverket do their maintenance according to a standard program, which means that every maintenance task will be done when the task limit occurs. This leads to a very long downtime for the aircraft in some occasions and very short downtime in others. The goal with this work is to reach a higher regularity of the aircraft operation. To reach a higher regularity for the operational needs, this work will present a hypothetic better maintenance concept for Swedish Maritime Administration. The concept is based on equalized maintenance structure, which means that every maintenance occasions are meant to take the same time to perform. This result will lead to easier planning and better maintenance overview of the aircraft operation. Different types of results have been presented depending on the size of the check cycle or if the engineering unit at the helicopter organization is going to use a reliability program in the future or not. Two with different types of check cycles and one, which can be considered as a future goal when a potential reliability program is in use.  

     

    The work of the equalized maintenance structure takes airworthiness limitation tasks in consideration and put them as “drop outs” besides the check cycle itself because of the high criticality in those items.

    Excel has been used to store and sort all the maintenance tasks, which are considered in this work, and pivot tables have been used to get an overview of the number of tasks in each interval. An aircraft reliability program has been suggested in the future due to the changes in escalation of intervals gives Sjöfartsverket the opportunity to optimize their equalized structure even further with less reduction of task intervals, a better task spread out and higher operational safety.

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  • 44.
    Gabrielsson, Johan
    Mälardalen University, School of Innovation, Design and Engineering.
    Development and documentation of process and routines for Continuous Airworthiness Management Organisation2012Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report provides a description of a thesis work in aeronautical engineering that was carried out at Patria Helicopters AB during the period February to April 2012.

    Patria have been responsible for the preservation of a Eurocopter EC135 since May of last year due to the fact that the previous owner went into receivership. A decision was made at the beginning of this year that the company would also take over the continuing airworthiness of the helicopter.

    This created the need for a CAME to be written as part of the application process to become an approved CAMO organisation.

    During the ten weeks at Patria the author has been working on the compilation of the exposition in accordance with Part M, Subpart G, M.A. 704 as well as all of the appendices that needed to be included with the application to Transportstyrelsen.

    The task has meant familiarizing one’s self with the rules and regulations of EASA Part-M and how the various sub-parts relate to each other. In addition to this, the routines and processes that were already established at Patria have also been examined.

    With the help of a compliance check list provided by Transportstyrelsen, “Anybodies CAME” and EASAs Part-M document, the different areas that needed to be addressed in the exposition were accomplished and thus describe the routines that are in place at Patria Helicopters AB which will ensure the continuing airworthiness of the aircraft managed by the company.

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    Examensrapport i flygteknik
  • 45.
    Gkoutzamanis, Vasilis G.
    et al.
    Aristotle Univ Thessaloniki, Dept Mech Engn, GR-54124 Thessaloniki, Greece.
    Kavvalos, Mavroudis D.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Srinivas, Arjun
    Aristotle Univ Thessaloniki, Dept Mech Engn, GR-54124 Thessaloniki, Greece.
    Mavroudi, Doukaini
    Aristotle Univ Thessaloniki, Dept Mech Engn, GR-54124 Thessaloniki, Greece.
    Korbetis, George
    BETA CAE SYST SA, GR-57500 Thessaloniki, Greece.
    Kyprianidis, Konstantinos G.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Kalfas, Anestis, I
    Aristotle Univ Thessaloniki, Dept Mech Engn, GR-54124 Thessaloniki, Greece.
    Conceptual Design and Energy Storage Positioning Aspects for a Hybrid-Electric Light Aircraft2021In: Journal of engineering for gas turbines and power, ISSN 0742-4795, E-ISSN 1528-8919, Vol. 143, no 9, article id 091019Article in journal (Refereed)
    Abstract [en]

    This work is a feasibility study of a 19-passenger hybrid-electric aircraft, to serve the short-haul segment within the 200-600 nautical miles. Its ambition is to answer some dominating research questions, during the evaluation and design of aircraft based on alternative propulsion architectures. The potential entry into service (EIS) is foreseen beyond 2030. A literature review is performed to identify similar concepts under research and development. After the requirements' definition, the first level of conceptual design is employed. The objective of design selections is driven by the need to reduce CO2 emissions and accommodate aircraft electrification with boundary layer ingestion engines. Based on a set of assumptions, a methodology for the sizing of the hybrid-electric aircraft is described to explore the basis of the design space, incorporating a parametric analysis for the consideration of boundary layer ingestion effects. Additionally, a methodology for the energy storage positioning is provided to highlight the multidisciplinary aspects between the sizing of an aircraft, the selected architecture (series/ parallel partial hybrid), and the storage characteristics. The results show that it is not possible to fulfill the initial design requirements (600 nmi) with a fully-electric aircraft configuration, due to the farfetched battery necessities. It is also highlighted that compliance with airworthiness standards is favored by switching to hybrid-electric aircraft configurations and relaxing the design requirements (targeted range, payload, battery technology). Finally, the lower degree of hybridization (40%) is observed to have a higher energy efficiency (-12% energy consumption) compared to the higher degree of hybridization (50%) and greater CO2 reduction, with respect to the conventional configuration.

  • 46.
    Gorges, Rami
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Gustafsson, Ellinor
    Mälardalen University, School of Innovation, Design and Engineering.
    SAAB-340, Nya inspektionsrutiner för ”Placards & Markings”2016Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report is a final thesis conducted by two students at the Academy of Innovation for Design and Technology at Ma ̈lardalens university in Va ̈ster ̊as, in collaboration with Nextjet.

    The purpose of this investigation is to explore the different ways in which we can improve the inspection of “Placards & Markings” for Nextjet’s SAAB- 340 aircrafts. This assesment is required by the government in the process of renewing/extending the ARC-airworthiness Review Certificate of the planes.

    The ARC-process is conducted according to the rules and regulations of the EASA, one of which is a review of the plane’s airworthiness.

    In this thesis we will explore the plausible ways of inspection while compa- ring and contrasting these different methods. The intent is to find the most adequate and reliable procedure at the lowest cost, with high security.

    We will focus on three chosen methods:

    • Visual inspection

    • ITS - intelligent transport system

    • Inspection of the aircrafts exterior with the help of a drone

    New technologies like ITS and drones are on the rampage and has many advantages. Both ITS and drones enables verifiability and are time-efficient methods. Despite this, the visual inspection method is currently most sui- table for Nextjet and their inspection of the ”Placards & Markings”. Visual inspection is an inexpensive alternative that requires no sophisticated equip- ment.

    A technical instruction must, according to the studied literature, have a structured format. Consideration should be given to the human factors that come into play during a visual inspection, which can be prevented if kept in mind when designing the instruction. The technical instruction that we designed needs to be tested in its real environment to properly evaluate its function. 

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    FULLTEXT01
  • 47.
    Grönberg, Gustav
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Klas, Gabriella
    Mälardalen University, School of Innovation, Design and Engineering.
    Undersökning kring sammanslagning av Air Hudik och Priority Aero Maintenance2015Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
  • 48.
    Grönstedt, Tomas
    et al.
    Chalmers University Gothenburg, Sweden.
    Au, Dax
    Aerodynamics and propulsion Institut Supérieur de l’Aéronautique et de l’Espace Toulouse, France.
    Kyprianidis, Konstantinos
    Cranfield University, Cranfield, Bedfordshire, UK.
    Ogaji, Stephen O. T.
    Cranfield University, Cranfield, Bedfordshire, UK.
    Low-Pressure System Component Advancements and Its Influence on Future Turbofan Engine Emissions2009Conference paper (Refereed)
    Abstract [en]

    Within the European research project EnVIronmenTALly Friendly Aero Engines, VITAL, a number of low pressure system component technologies are being investigated. The emerging progress will allow the design of new power plants providing a step change in engine fuel burn and noise. As part of the VITAL project a Technoeconomic and Environmental Risk Assessment tool, the TERA2020, is being developed. Within this tool, means to assess the impact of component technology progress on the engine/aircraft system level has been implemented. Sensitivities relating parameters traditionally used to describe component performance, such as allowable shaft torque, low pressure turbine stage loading, fan blade weight and system level parameters have been established. This allows a direct assessment of the impact of component research progress on the VITAL power plant CO2 and noise emissions.

  • 49.
    Grönstedt, Tomas
    et al.
    Chalmers University of Technology, Sweden.
    Kyprianidis, Konstantinos
    Cranfield University Bedfordshire, United Kingdom.
    Optimizing the Operation of the Intercooled Turbofan Engine2010Conference paper (Refereed)
    Abstract [en]

    The performance of an intercooled turbofan engine is analysed by multidisciplinary optimization. A model for making preliminary simplified analysis of the mechanical design of the engine is coupled to an aircraft model and an engine performance model. A conventional turbofan engine with technology representative for a year 2020 entry of service engine is compared to a corresponding intercooled engine. A mission fuel burn reduction of 4.3% is observed. The results are analysed in terms of the relevant constraints such as compressor exit temperature, turbine entry temperature, turbine rotor blade temperature and compressor exit blade height. It is then shown that a separate variable exhaust nozzle mounted in conjunction with the intercooler together with a variable low pressure turbine may further improve the fuel burn benefit to 5.5%. Empirical data and a parametric CFD study is used to verify the intercooler heat transfer and pressure loss characteristics.

  • 50.
    Hamza, Sherko
    Mälardalen University, School of Innovation, Design and Engineering.
    Lyftanordning till BAE Jetstream J322017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Anledningen till att konstruera en lyftanordning är att använda den vid påmontering och avmontering av bagagepoden på flygplanstypen BAE Jetstream J32. I dagsläget sker inget underhåll på hydrauliksystemet som är under bagagepoden på Edströmska gymnasiet,men med hjälp av lyftanordningen ska detta vara möjligt framöver. Med ritningarnas hjälpkan elever på Edströmska gymnasiet eller arbetare på en mekanisk verkstad tillverkalyftanordningen. Lyftanordningen räknas som ett redskap till att underhålla flygplanet. Som ett resultat av lyftanordningens design kommer underhållsskador samt arbetsskador minska. Det finns en befintlig lyftanordning på Edströmska gymnasiet men den är inte anpassad för att av- och påmontera bagagepoden. En studie har genomförts över hur alla lyftar på marknaden fungerar, och hur de ser ut i detalj för att vidare kunna konstruera en lyft. En grundlig litteraturstudie om mekanik samt materiallära har gjorts för att definiera de egenskaper som krävs för att konstruera lyften. Konstruktionen på lyften ärspecifikt gjort för flygplanstypen Jetstream J32. Det unika med konstruktionen är att lyftanordningenär hopfällbar, vilket resulterar i att lyftanordningen kräver lite utrymme samtidigt som risken för krock med andra föremål i verkstaden minskar. I dagsläget finns det ingen dokumentation som beskriver att ett arbete med att skapa en lyftanordning för flygplanstypen BAE JetstreamJ32. Liknade projektarbete på högskolenivå har gjorts tidigare för framtagning av en portabel patientlyft. Arbetet gick ut på att framställa en lämplig patient-lyftanordning för ambulansflygplan. Där användes också saxlyftprincipen.

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    EXAMESARBETE I FLYGTEKNIK
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