The objective of this diploma thesis is to perform a complete risk assessment of an insulation blanket’s trial installation for an Airbus A320 aircraft. Technical and functional requirements have been described in order to understand the changes operated on the blanket. Through the study of non-conformities and graphs depicting deliverables versus time, quality issues and time delays are tracked in the best possible way in order to identify risks. Appropriate risk tables and matrix were chosen as a frame for this assessment. Risks associated with the trial installation of the new insulation blankets were then assessed, prioritized according to their criticality and placed automatically on a risk matrix using a VBA program. Mitigationactions were finally proposed and validated to achieve the main objective of this risk assessment: to annul the occurrence and to decline the impact of all potential unforeseen turns of event described in this report.

The purpose of the present master thesis is to optimize the current fuel tank simulations procedure for the next generation of JAS 39 Gripen ghters developed by SAAB AB. The current simulation process involves three dierent steps performed in three dierent computer environments. While the procedure works reasonably well on the fuel tank models of the previous version of the aircraft, it is too slow for the new Gripen tank models and their high level of detail. An optimized version of the procedure is put forward, which allows for tank analysis and fuel system simulation within reasonable time frames. Suggestions are made for future improvements.

The feasibility of implementing an active flow control system in ground vehicles is investigated through detached-eddy simulations of the Windsor model. This is done in the open-source CFD code OpenFOAM. Forcing is done with a zero-net-mass-flux actuator, which is modeled as a sinusoidal velocity boundary condition through slots located at the rear edge of the roof. Simulations are done in three steps: 2D, semi-3D and 3D, to give an understanding of different flow phenomena, and a parameter study is performed. Results show that drag can be reduced mainly by reducing the strength of the vortex shedding process, with a gradual decrease in effectiveness from 2D to 3D. A small drag reduction is achieved in semi-3D, and a lift reduction is achieved in 3D. DES methodology is shown to work well when simulating active flow control.

Complex systems can be modelled using graphical tools such as Simulink. Here, the equations of motion in combination with the necessary data were modelled using Simulink to describe and analyze the unmanned Predator C Avenger. The aerodynamic data was obtained from the potential 　ow solver dwfs (dry water 　ow solver). The Simulink model is initially in steady state, disturbances are then added to investigate the 　ying qualities of the aircraft both in the longitudinal and lateral direction. The modes calculated from the model are compared to the modes produced from the linearized matrices containing the aerodynamic derivatives. The other task for the Simulink model is for some of its subsystems to be integrated with the simulation program ARES, which is used at Saab. The Simulink subsystems are converted into C code and are built into ARES. The rst expected result is that the modes from the linearized model should indicate the values of the modes from the Simulink model. The largest dierence - which regards the spiral mode - was about 24% and assumed acceptable as the approximative solution for this mode is considered poor [4]. The other dierences were at most about 15%. The second expected result is that the outputs from simulating the complete model using Simulink should match the outputs obtained from simulating through ARES connected to the Simulink subsystems. It was the discovered that the obtained results - which are the values of the longitudinal trim parameters and the modes - from Simulink match almost exactly the results from ARES with some few deviations. The trim results had a maximum difference of about 6% and the values of the modes had a maximum dierence of about 10% and also assumed acceptable.

In-service support engineers often have to answer derogations requests regarding impacts on compressor blades. The stress concentration factor is a physical quantity helping them to take the decisions : it is a measure of the local increase of the stress due to the impact. Several techniques already exist to derive it like Petersons' abaci giving it regarding the geometrical parameters of the impact. They are user friendly but conservative in practice. The most accurate method is zoom-calculation : a Finite Element Model is created to precisely measure the stress concentration factor. This effective approach is however very time-consuming. In between, Snecma engineers developed a few years ago a law on the form of abaci derived from a zoom-calculation results database. The main purpose of this thesis is to create laws regarding new geometrical parameters and increase the size of the database following on from the work already carried out. FEM models depending on various parameters are thus created to derive stress concentration factors. A deep difference from what has been done before rests on the method : a calculation chain is developed to get results on different sets of impact parameters. It enables to easily and quickly update the mesh on the models and thus to consider numerous defect geometries. The final results of the study are a set of abaci giving the stress concentration factor due to the impact regarding its geometrical parameters.

Silicon carbide (SiC) shows promise as an increasingly widespread material for aerospace mirror systems. It has already been successfully used in recent space programs, with and without Chemical Vapor Deposition (CVD). The additional processes and costs generated by CVD make the alternative of SiC without CVD more practical, as long as stray light specifications are met. Nonetheless, theoretica lmodels remain underequipped to describe properly the scattering effects generated by the porous surface of SiC. The present study, performed at EADS Astrium in Toulouse, aimed at developing an analytical model to relate SiC roughness to Bidirectional Reflectance Distribution Function (BRDF). Series of measurements of roughness maps and BRDFs were carried out enabling to assess the abilities of Astrium subcontractors to measure SiC properties. A fast numerical tool was developed to compute BRDFs from roughness maps. A comparison between computed and measured BRDFs was thus made possible. The K-correlation model proved to successfully describe scatter properties of SiC CVD and an adjustment of this model was proposed for SiC without CVD. Because of the limitations of optical profilometry in measuring pores of low dimensions and remnant difficulties in BRDF measurements, reliable data is still required to continue these first steps and eventually develop models that will take SiC pores into account.

Cars have been used frequently for over a hundred years now, and there’s been a fantasy for a long time about flying cars in the future. Airborne travel gives the freedom of three dimensions and all the benefits that comes with it. There’s straighter paths, ability to travel faster and it can be the source of fantastic views. TF-X is a concept developed by Terrafugia. The concept is a vehicle that can be driven on land like a car, but also be able to take off vertically and then fly through the air like an airplane. TF-X has wings that can be folded along the side of the vehicle, and has propellers mounted on the far edge of the wings that can be rotated between a vertical and horizontal position. This project was designed to develop a model of TF-X and test the flight potential that this vehicle can achieve. The resulting model has a length of 4.9 m, a width of 2.45 m and a height of 1.82 m when the wings are folded down. The wingspan under flight is 5.5 m. The vehicle has a PW600 turbofan engine that provides thrust during horizontal flight, and 10 Emrax 207 electrical engines that powers two propellers during vertical flight. These engines are powered by 250 kg jet fuel and 100 kg lithium batteries respectively. This gives a vertical flight time of approximate 3 minutes and with a cruising speed of 89 m/s a range of 400 km. / Bilar har använts flitigt i över hundra år, och det har länge funnits en fantasi om flygande bilar i framtiden. Luftburen färd ger friheten av tre dimensioner och alla de fördelar det innebär. Det är rakare färdväg, går att färdas i högre hastigheter och det ger även upphov till fantastiska vyer. TF-X är ett koncept som är utvecklat av Terrafugia. Konceptet består av ett fordon som kan köras som en bil på land, men ska även kunna lyfta vertikalt och sedan flyga som ett flygplan i luften. TF-X har vingar som kan vikas ner längs med fordonets sidor, och har propellrar monterade längst ut på vingarna som kan vridas mellan vertikalt och horisontalt läge. Detta arbete har gjorts för att ta fram en modell av TF-X och testa de potentiella flygförmågor som denna farkost kan uppnå. Den resulterande modellen har en längd på 4,9 m, en bredd på 2,45 m och en höjd på 1,82 m när vingarna är nedfällda. Vingspannet under flygfärd är på 5,5 m. Fordonet har en PW600 turbofläktmotor som ger dragkraft under horisontell flygning, och 10 st. Emrax 207 elmotorer som driver två propellrar under vertikal flygning. Dessa motorer drivs av 250 kg jetbränsle respektive 100 kg litium-batterier. Detta ger en vertikal flygtid på c:a 3 minuter och med en marschfart på 89 m/s en maximal räckvidd på 400 km.

This report is written in the purpose to investigate the mechanical forces and characteristics related to a propeller driven aircraft in the Earth’s atmosphere. It’s written as a thesis project during the spring semester of 2014 and graded accordingly. Thanks Arne Karlsson for fruitful discussions. Also thanks to Simon Leijonmarck for help with useful discussions concerning structural batteries. / Denna rapport är skriven i ändamålet att undersöka de mekaniska krafter och egenskaper som rör ett propellerdrivet flygplan i jordens atmosfär. Den är skriven som ett examensarbete under vårterminen 2014 och betygsätts därefter. Tack Arne Karlsson för givande diskussioner. Även tack till Simon Leijonmarck för hjälp med givande diskussioner rörande strukturella batterier.

Unmanned aerial vehicles (UAV’s) are nowadays greatly appreciated. The advantage over manned airplanes are great since UAV’s can be much smaller and therefore lighter. The goal of this project is to evaluate the performance of an environmentally friendly UAV using only lithium-ion batteries. This in doing monitoring of agriculture or road traffic situations for example. In order to determine every parameter of the airplane the electric motor from Sineton and inspiration from other small airplanes composed the starting point. Some important specifications were a maximum weight of 25 kg, a cruise time of at least three hours and a cruise speed of at least 100 km/h. In order to reach these goals and determine the parameters of the airplane, the literature General Aviation Aircraft Design: Applied Methods and Procedures by Gudmundsson and the software Matlab were used. This literature contain detailed sections that process every aspect of an airplane. By using this literature, the choice for instance fell upon using a four-bladed propeller in order to minimize the diameter and a semi-tapered wing with an airfoil from NACA. The wing and the tail were also analyzed in the software XFLR5. When all the parameters of the airplane started to take shape, evaluations were made in order to secure adequate performance regarding take-off, climb, stability and landing.  The choice of material and power plant are the ones that affect the amount of CO2 emission the most. Since carbon fiber has a higher yield strength and a much lower density, the construction doesn’t need as much material. This some what negates the fact that carbon fiber is much more expensive than aluminium. Besides a lighter airplane requires less energy in use. Concerning the source of energy, lithium-ion batteries does add to CO2 emission in its manufacturing state. In this case it will take around 200 hours of use before the emission from e.g. gasoline would be have to become larger than the initial emission of the manufacturing of the batteries. With this said we consider the use of both carbon fiber and lithium-ion batteries the right choice concerning the environmental aspect for an airplane like this. / Obemannde flygplan har i dagsläget ett stort användnings område. Fördelarna är stora jämfört med bemannde flygplan då de kan bli avsevärt mindre. Denna studie syftar till att undersöka hur ett miljövänligt obemannat flygplan med endast litiumjonbatterier som energiförsörjning står sig inför uppgifter som att övervaka jordbruk eller trafikflöden till exempel. Den elektriska motorn från Sineton tillsammans med inspiration från andra mindre flygplan utgjorde utgångspunkten. Med dessa parametrar kunde resten av flygplanets utformning bestämmas. Några viktiga mål innefattade bl.a. en maxvikt på 25 kg, en flygtid på tre timmar och en marschfart på lite drygt 100 km/h. För att uppnå målen och bestämma utformingen på flygplanet användes framför allt Gudmundssons bok General Aviation Aircraft Design: Applied Methods and Procedures samt programvaran Matlab. I boken återfinns detaljerade sektioner om flygplanets alla delar. Med hjälp av denna litteratur valdes bl.a. en fyrbladig propeller för att minimera diametern och en s.k. ”semitaperedwing”-konfiguration till huvudvingen med en vingprofil från NACA. Huvudvingen och stabilisatorn analyserades även i programvaran XFLR5. När flygplanets parametrar började ta form gjordes även analyser för att säkerställa en tillfredställande prestanda gällade start, stigning, stabilitet samt landning.  Valet av drivsystemet och materialet är de största faktorerna gällande utsläpp av CO2. Då kolfiber både har en högre sträckgräns än aluminium och även en avsevärd lägre densitet behövs inte lika mycket material. Detta upphäver till viss mån den högre kostnaden för kolfiber vid tillverkningen. Dessutom innebär ett lättare flygplan att mindre energi går åt vid användning. Gällandeenergiförsörjningen bidrar batteritillverkningeen till ett signifikant utsläpp av CO2. I detta fall räcker det med lite drygt 200 flygtimmar innan utsläppet från    t ex bensin hade kommit ikapp initalutsläppet vid tillverkningen av litiomjonbatterierna. Med detta sagt anser vi att både användning av kolfiber och litiumjonbatterier är det rätta valet ur miljösynpunkt i ett sådant här typ av flygplan.

This thesis presents an aircfaft concept, The Joyride, supposed to satisfy the future demand for sustainable hobby aircrafts.  The work was done through research on evironmental friendly aircfaft complimented by lectures on aircfaft dynamics held by supervisor Arne Karlsson.  A propulsion system was designed and two different future energy sources were examined.  Sizing and performance analyses were exectued in an iterative trial and error fashion to fulfill the specified aims for the aircraft. The final results present a zero-emissions, light weight, blended wing body aircraft. The Joyride has got a maximum takeoff gross weight of less than 800 kg, wingspan of 16 m, wingarea of 24 m2, cruise altitude of 6000 m and a maximum range of 850 km. It is equipped with an electric motor with a peak power of 120 kW-161 hp.  This makes and completing a 180° turn in just over 6 seconds, in other words perfectly suited for an aircraft enthusiast. It is the authros' belief that The Joyride is possible to realize within a timeframe of 50 years.