The largest and most important fluid system in an aircraft is the fuel system. Obviously, future aircraft projects involve the design of fuel system to some degree. In this project design methodologies for aircraft fuel systems are studied, with the aim to shortening the system development time. This is done by means of illustrative examples of how optimization and the use of matrix methods, such as the morphological matrix, house of quality and the design structure matrix, have been developed and implemented at Saab Aerospace in the conceptual design of aircraft fuel systems. The methods introduce automation early in the development process and increase understanding of how top requirements regarding the aircraft level impact low-level engineering parameters such as pipe diameter, pump size, etc. The morphological matrix and the house of quality matrix are quantified, which opens up for use of design optimization and probabilistic design. The thesis also discusses a systematic approach when building a large simulation model of a fluid system where the objective is to minimize the development time by applying a strategy that enables parallel development and collaborative engineering, and also by building the model to the correct level of detail. By correct level of detail is meant the level that yields a simulation outcome that meets the stakeholders’ expectations. The experienced gained at Saab in building a simulation model, mainly from the Gripen fuel system, but also the accumulated experience from other system models, is condensed and fitted into an overall process.

<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.

Critical steps in the design process is the gathering of data, processing the data into a useful form of information (a design concept) which meets specific needs, passing this refined design solution down the path to production, where it is released into the larger environment. With in the designing process there are multiple feedback loops as the solution becomes more refined. Even as it reaches the final end user, other design refinement feedback loops continue as new and improved products or systems. Along with the interdisciplinary teams involved with the product/system development, the more complexity the product or system becomes the more critical the organization of the data becomes. This paper will present and test a concept of a design feedback and feed forward communication tool for product/system design that uses Dr. Walter A. Schaer s Three Functions of an Artifact as the methodological structure for design development. The essence of this design tool is the merging of a new communication system within an existing methodology of organizing complex systems into a morphological matrix, developed by Dr. Walter A. Schaer, based on the Charles Morris s work on semiotics. This communication tool is a new feedback / feed forward mechanism which correspond with the semiotic structure in a morphological matrix to assist the designer develop design solutions. The research will measure the success rate of the tool in the design process, examine of how the designers took advantage of the new tool, and evaluate their perception of its usefulness.

Developments in electric technologies have the potential to increase the efficiency and performance of commercial aircraft. However, without proper architecture innovation, technology developments at the subsystem level are not sufficient to ensure successful integration. Adaptations to existing architectures work well when trades are made strictly between equivalent systems which fulfill and induce the same functional requirements. However, this approach does not provide the architect with adequate flexibility to integrate technologies with differing functional and physical interfaces. Architecture redefinition is required for proper implementation of non-traditional and innovative architectural elements. A function-based process for innovative architecture design was developed to provide flexibility in the definition of candidate architectural concepts. Tools and methods were developed which facilitate the definition and exploration of a function-based architectural design space. These include functional decomposition, functional induction, dynamic morphology, adaptive functional mapping, reconfigurable mission definition, and concept level system installation. The Architecture Design Environment (ADEN) was built to integrate these tools and to facilitate the definition of physics-based models in evaluating the performance of candidate architectures. Using functions as the foundation of this process assists in mitigating assumptions which traditionally govern architecture structures and offers a promising approach to architecting through flexible conceptualization and integration. This toolset provides the framework wherein knowledge from conceptual, preliminary, and detailed design efforts can be linked in the definition of revolutionary architectures.

Målet med detta projekt har varit att utveckla en monteringsvänlig och kostnadseffektiv ljuddiffuser, en komponent som inte ska påverka ljudnivån och luftflödet för mycket, tillskillnad från den befintliga lösning som idag används i 3nine AB:s oljedimavskiljare. Examensarbetet följer den produktutvecklingsprocess som redogörs i boken Produktutveckling – Konstruktion och design av Karl T. Ulrich och Steven D. Eppinger. Där arbetet har anpassats för tidsramen på 10 veckor och delats upp i fyra faser. Fas1 – Förstudie, Fas 2 – faktainsamling, Fas 3 – Genomförande och Fas 4 – Rapportering. Den lösning som används idag består av fem vikta bitar sträckmetall som har sytts ihop med ståltråd, ljuddiffusern tar lång tid att montera ihop och att montera ned i maskinen. De fem vikta bitarna sträckmetall har vassa kanter efter klippning som försvårar monteringen ytterligare. En ljuddiffuser har en kostnad på 100 kr/st att framställa. För denna lösning togs mätvärden i 3nine AB:s verkstad fram som agerar som referensmätvärden, monteringstid – 333 [s], ljudnivå – 68 [dB], luftflöde – 319 [m ³/h] och DFA – index (mätvärde för monteringsvänlighet) – 5,4 %. Där 100 % ses som optimal monteringsvänlighet och högre DFA-index leder till reducerade kostnader. Då luft strömmar genom maskinen så påverkar detta mätvärdena och möjlig design av ny prototyper, men strömningslära är kunskaper som vi saknar och detta analyser med avseende på detta avgränsades bort. Genom Idéutvecklingsprocesser som Brainstorming, 6-3-5 Brainwritning, Morfologiskmatris, Pughmatris, konceptskisser, Virtuella koncept (3D-CAD) och friformsframställning (3D-utskrivning av prototyp) så togs fem prototyper fram som sedan testades för monteringstid, ljudnivå, luftflöde och DFA-index. Dessa tester resulterade i att det var en prototyp som utmärkte sig med förbättrade resultat jämfört med referensmätvärdena av befintliga ljuddiffusern. Mätvärden för prototypen ”45° väggen”, monteringstid – 16 [s], ljudnivå – 65 [dB], luftflöde – 342 [m ³/h] och DFA – index (mätvärde för monteringsvänlighet) – 93 %. Risk – och FEM-analys genomfördes på prototypen för att identifiera svagheter i konstruktionen, lösningar på dessa rekommenderas i form av små förändringar som t.ex. rundningar vid hörn. Dessa mätvärden redogör att den framtagna lösningen är bättre än dagens lösning och rekommenderas att implementeras och vidareutvecklas av företaget / The aim of this project has been to improve the existing noise diffuser used currently today in the oil-separatingmachines developed by 3nine AB. By reducing noise levels, increasing the air flow, increasing the “ease of assembly” and making it more cost effective. The thesis follows the product development process described in the book “Product Development - Construction and Design” by Karl T. Ulrich and Steven D. Eppinger. The work was adapted for a 10-week timeframe and divided into four phases. Phase 1 - Pre-Study, Phase 2 – Information gathering, Phase 3 - Implementation and Phase 4 - Reporting. The solution used today consists of five folded pieces of stretch metal that have been sewn together with steel wire, the noise diffuser takes a long time to assemble and to fit into the machine. The five folded pieces of stretch metal have sharp edges after cutting, which further complicates the assembly. The production cost for each diffuser is 100 kronor. For the present solution, the measurement values taken at 3nine AB's workshop were set as reference values, assembly time - 333 [s], noise level - 68 [dB], airflow - 319 [m³ / h] and DFA-index (measurement value for ease of assembly) - 5.4%. DFA-index when 100% is seen as the optimal ease of assembly and a higher DFA-index leads to reduced costs. As air flows through the machine, this affects the measured values and possible design of new prototypes, but fluid mechanics is one knowledge we lacked and therefor analysis of this was not possible and delimited. Through Idea Development Processes such as Brainstorming, 6-3-5 Brainwriting, Morphological Matrix, Pugh matrix, Concept Sketches, Virtual Concepts (3D-CAD) and Rapid prototyping (3D-prototype printing), five prototypes were produced, then tested for assembly time, noise level, airflow and DFA -index. These tests resulted in a prototype that featured improved results compared to the reference values of the existing noise diffuser. Measurement values for prototype "45° wall" where assembly time - 16 [s], noise level - 65 [dB], airflow - 342 [m³ / h] and DFA index - 93%. Risk-analysis and FEA was carried out on the same prototype to identify weaknesses in the design. The solutions to these weaknesses are recommended in the form of small design changes such as rounded sharp corners. These measured values state that the solution developed is better than today's solution and is recommended to be implemented and further developed by the company.