Laboratory and field investigations during the past ten years have demonstrated that certain microorganisms can cause deleterious effects in jet fuel tank systems. These investigations have brought about new concepts concerning the mechanisms of utilization of certain constituents in jet fuel tanks by microorganisms. Since the presence of microorganisms is inevitable in fuel systems, research efforts have been directed towards identification and determination of the types of microorganisms which can utilize jet fuel hydrocarbons, fuel additives, polyurethane foam structural materials, and particular hydrocarbons present in the fuel.

In this thesis a method for verification, validation and uncertainty quantification (VV&UQ) has been tested and evaluated on a fuel transfer application in the fuel rig currently used at Saab. A simplified model has been developed for the limited part of the fuel system in the rig that is affected in the transfer, and VV&UQ has been performed on this model. The scope for the thesis has been to investigate if and how simulation models can be used for certification of the fuel system in a fighter aircraft. The VV&UQ-analysis was performed with the limitation that no probability distributions for uncertainties were considered. Instead, all uncertainties were described using intervals (so called epistemic uncertainties). Simulations were performed on five different operating points in terms of fuel flow to the engine with five different initial conditions for each, resulting in 25 different operating modes. For each of the 25 cases, the VV&UQ resulted in a minimum and maximum limit for how much fuel that could be transferred. 6 cases were chosen for validation measurements and the resulting amount of fuel transferred ended up between the corresponding epistemic intervals. Performing VV&UQ is a time demanding and computationally heavy task, which quickly grows as the model becomes more complex. Our conclusion is that a pilot study is necessary, where time and costs are evaluated, before choosing to use a simulation model and perform VV&UQ for certification. Further investigation of different methods for increasing confidence in simulation models is also needed, for which VV&UQ is one suitable option.

Within automotive industry, Noise, Vibration and Harshness (NVH) has emerged to be one of the main research topics. Unlike attributes such as vehicle safety, drivability, and durability which are functionality criteria, NVH is closely tied to quality and comfort of the ride. The recent trend in consumer market shows that NVH is becoming increasingly important in purchasing decisions and can significantly affect competitive edge of vehicles. Among various factors that contribute to vehicle noise, pressure pulsation inside vehicle fuel system has been subject to studies for several decades. In gasoline vehicles, with the introduction and wide spread of returnless fuel delivery system, the pressure pulsation phenomenon has become more and more prominent and has raised several issues, including noise. Similar phenomenon can be found in EVAP system where pressure is small. However, the information regarding pressure pulsation and noise issue in EVAP system is very limited. This thesis investigated the noise issue caused by pressure pulsation inside EVAP system of a current production vehicle by one of the major automotive Original Equipment Manufacturers (OEM). There are two main parts in this research. First part is to build a test stand integrating the original parts provided by the OEM to re-create the noise, then to observe and collect data on the noise issue to understand the noise generation mechanism. Second part of this research is to, through literature survey, generate ideas on noise reduction, and then to test these ideas. Due to limited information, literature survey was focused on researches done on the fuel delivery system. By collecting and analyzing pressure data on various running conditions, utilizing inspection camera, and carefully designed experiments, this research made findings on pressure pulsation and noise phenomenon, examined possible scenarios for the noise generation mechanism, and provided key evidences regarding various components and their effects on the pressure pulsation/noise. This thesis presented 8 different approaches to achieve noise reduction. Among those, 5 focused on pressure pulsation attenuation, which heavily drew inspiration from pulsation attenuation methods used in fuel delivery system. The methods tested in this thesis achieved various degree of success in noise reduction. However, each had its own drawbacks: they caused flow restriction in the line, and/or reduced the vacuum level going to the fuel tank system, and/or required design changes on critical parts in the system.

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Dans de nombreux domaines industriels, l’innovation est mise en œuvre de manière incrémentale en cherchant à optimiser un concept donné. Ce type d’innovation est efficace sur le court terme, permettant d’arriver à améliorer le système avec une prise de risque limitée. Cependant, cette approche réduit fortement les opportunités d’amélioration future de ces systèmes. Pour faire face à des nouveaux besoins émanant des clients, l’innovation de rupture s’impose dans une vision long terme. Un changement radical de concept permet en effet de dégager des marges fonctionnelles permettant d’améliorer significativement le système. Le but de ces travaux de thèse a été, d’une part, de proposer un cadre méthodologique pour l’étude conceptuelle d’architectures de systèmes de puissance en rupture. Ceci consiste en la spécification des nouveaux besoins, la génération d’architectures système fortement innovantes, ainsi que la sélection des architectures les plus pertinentes. En s’appuyant sur une approche d’ingénierie système, ainsi que sur des techniques à l’état de l’art dans les domaines de la recherche de solutions innovantes (KCP, Brainwritting, Diagramme KJ), la combinaison des concepts (matrice morphologique) et de l’aide à la décision multicritères (TOPSIS, MAUT), une approche originale a été proposée. La méthode proposée a été appliquée au cas du circuit carburant d’un moteur d’hélicoptère chez l’industriel Safran Helicopter Engines. Ce contexte applicatif a permis de mettre en œuvre et d’évaluer les approches proposées dans un environnement industriel réel. Un outil implémenté sous Microsoft Excel a été développé pour le déploiement de la méthodologie proposée dans l’entreprise. / In several industries, incremental innovation has been used. This approach aims at optimizing a given design. It is efficient in the short term, and enables to improve the system at low risks. Anyway, incremental innovation implies a reduction in the capacity of future improvement. In order to deal with new customer needs, radical innovation is a must in a long-term consideration. Indeed, these radical changes allow to create new functional margins, enabling to make the system even better. The aim of this thesis work is, on the one hand, to propose a methodological framework for the conceptual design of radically innovative power system architectures. This implies tomorrow’s needs specification, strongly innovative architecture generation and best architectures selection. Based on a systems engineering approach, as well as state of the art techniques in the domain of creativity (KCP, Brainwritting, KJ Diagram), concepts combination (morphological matrix) or mutlicriteria decision making (TOPSIS, MAUT), an original approach has been proposed. On the other hand, this methodology has been implemented in an industrial framework in the case of a helicopter engine fuel system at Safran Helicopter Engines. This has enabled to obtain a return of experience on the industrial application of this methodology. A tool has been developed using Microsoft Excel for the industrial deployment of the methodology.

<p>To simplify troubleshooting and reliability of a process, a diagnosis system can supervise the process and alarm if any faults are detected. A diagnosis system can also identify one, or several faults, i.e. isolate faults, that may have caused the alarm. If model-based diagnosis is used, tests based on observations from the process are compared to a model of the process to diagnose the process. It can be a hard task to find which tests to be used for maximal fault detection and fault isolation. Structural Methods require not very detailed knowledge of the process to be diagnosed and can be used to find such tests early in the design of new processes. Sensors are used to get observations of a process. Therefore, sensors placed on different positions in the process gives different possibilities for observations. A specific set of sensors are in this work called a sensor configuration. </p><p>This thesis contributes with a method to predict and examine the fault detection and fault isolation possibility. By using these two diagnosis properties, a suitable sensor configuration is computed and tests to be used in a future diagnosis system are suggested. For this task an algorithm which can be used in the design phase of diagnosis systems, and a Matlab implementation of this algorithm are described. </p><p>In one part of this work the Matlab implementation and the algorithm are used to study how a model-based diagnosis-system can be used to supervise the fuel system in an Unmanned Aerial Vehicle (UAV).</p>

<p>This report is one part of a masters thesis in mechanical engineeing. Is is executed at the Department of Mechanical Engineering at Linköping Insitute of Technology in cooperation with Saab Aerosystems in Linköping.</p><p>A tool for concept generation called a quantified interactive morphological matrix has been created. It is based on rules of thumb and approximations concerning aircraft fuel systems.</p><p>The tool can be used for discarding bad concepts, with regard to weight, power consumption and MTBF, during the concept phase of a fuel system design process. The tool is ready for calibration towards a future specific area of use. It is open for validation and optimization and is specifically designed to be easily modified for different future products.</p><p>Suggestions for future use has been given concerning expansion, implementation, validation and optimization.</p>

This report is one part of a masters thesis in mechanical engineeing. Is is executed at the Department of Mechanical Engineering at Linköping Insitute of Technology in cooperation with Saab Aerosystems in Linköping. A tool for concept generation called a quantified interactive morphological matrix has been created. It is based on rules of thumb and approximations concerning aircraft fuel systems. The tool can be used for discarding bad concepts, with regard to weight, power consumption and MTBF, during the concept phase of a fuel system design process. The tool is ready for calibration towards a future specific area of use. It is open for validation and optimization and is specifically designed to be easily modified for different future products. Suggestions for future use has been given concerning expansion, implementation, validation and optimization.

To simplify troubleshooting and reliability of a process, a diagnosis system can supervise the process and alarm if any faults are detected. A diagnosis system can also identify one, or several faults, i.e. isolate faults, that may have caused the alarm. If model-based diagnosis is used, tests based on observations from the process are compared to a model of the process to diagnose the process. It can be a hard task to find which tests to be used for maximal fault detection and fault isolation. Structural Methods require not very detailed knowledge of the process to be diagnosed and can be used to find such tests early in the design of new processes. Sensors are used to get observations of a process. Therefore, sensors placed on different positions in the process gives different possibilities for observations. A specific set of sensors are in this work called a sensor configuration. This thesis contributes with a method to predict and examine the fault detection and fault isolation possibility. By using these two diagnosis properties, a suitable sensor configuration is computed and tests to be used in a future diagnosis system are suggested. For this task an algorithm which can be used in the design phase of diagnosis systems, and a Matlab implementation of this algorithm are described. In one part of this work the Matlab implementation and the algorithm are used to study how a model-based diagnosis-system can be used to supervise the fuel system in an Unmanned Aerial Vehicle (UAV).

This diploma thesis deals with the Common-Rail fuel system. The aim of this work is to develop an overview of development of the fuel-injection system. The first part is devoted to the description of the selected fuel system. All the parts of the system are described and explained there. Also the explanation of the management of the injection is included. Subsequently, other variants of the fuel system are described here. Further parts focuse on the diagnostic instruments and measuring emissions, also operational materials are described and divided in there. The last part of the thesis is devoted to the economic calculations which were made from the perspective of the economy operation of motor vehicles. The work also includes an evaluation of the measurements results and determines the appropriateness of the use of the Common-Rail fuel system for vehicles.