The interest for Flapping Wing Micro Air Vehicles (FWMAV) is growing. With this comes a need for future users to test and evaluate these vehicles with simulations. This study presents a first iteration of an implementation of a FWMAV in FLAMES Simulation Framework. An aerodynamic model based on the widely used quasi-steady blade element approach is presented and a first linearised version is implemented in FLAMES. The simulation model is capable of both manual and autonomous flight. With the first person view a pilot can investigate buildings and objects. The study gives an idea of how FLAMES can be used for this type of simulations. FLAMES provides a good environment for testing the vehicle both individually and in a context with other units.

The use of military UAV’s has become increasingly popular amongst the military powers of the world. But most of these UAV’s lack the vertical take-off and landing (VTOL) ability. This report investigates the quadrotor which is an excellent VTOL platform. The main disadvantage that the quadrotor platform possesses is that it suffers from poor performance if compared to airplanes. Quadrotors lack the endurance and the capability to carry heavy payloads. An effort is to be done to investigate the possible application area of use for the quadrotor platform from a military point of view. In order to solve these problems, two COTS (Commercial off the Shelf) quadrotors has been bought and a number of test flights have been performed with them. The results from these tests have been evaluated in MATLAB and a number of simulation models have been created in order to get a clear picture of the quadrotors potential. Rotorcraft such as the quadrotor is affected by the aerodynamic phenomena of induced power, this phenomena is important to understand when designing a control system for the quadrotor and when optimizing its endurance. A number of suggestions for how to improve the quadrotor platform have been proposed such as using ducted propellers, hybrid fuel systems, gyroscopes, and micro technology. A simulation model has been created that predicts the time that a quadrotor of a given size carrying different payloads could maintain itself in hover, this model show that battery based quadrotors are limited in how big they can be made. Much work has been dedicated to the extended sight concept where the quadrotor is intended to be powered by a cable and serve as a pair of extra eyes to an army vehicle such as a tank in an urban environment. Most of the technical difficulties for this concept has been defined and solved, these are mainly electrical difficulties and work on a demonstrator for this concept has been started. All these investigations points towards that the military would benefit from having quadrotors in their arsenal, they could be used for reconnaissance, placing out surveillance equipment and resupplying soldiers behind enemy lines.

Air intake related aerodynamic aspects of an air breathing cruise missile are analyzed. A method for thrust and drag accounting is established, and, based on that, a partial simulation model for the thrust and intake spillage drag force of the missile is developed. The model combines wind tunnel data with analytical data. The intake spillage force has two components, pre entry force and cowl force. The pre entry force can be computed relatively easily, while the cowl force depends strongly upon actual intake geometry and no general method exists. An approximate cowl force is computed based on available data. The accuracy of the cowl drag results is difficult to predict, as no complete theoretical model is available, and the partial models published cite no accuracy limits. The cowl drag results need further verification through wind tunnel tests or CFD analysis. However, spillage force results are produced that are in the magnitude of 30% of total drag, which is expected. Also, dependencies on known variables and trends are as expected. Finally, flight test profiles in order to validate the model are suggested.

The objective of this study was to evaluate the 　ying qualities of a light unmanned aerial vehicle (UAV) developed by the Thai company AVIA Satcom Co., Ltd. Based on the study changes in design was to be suggested to meet stability requirements and recommendations from European Aviation Safety was based on two dierent analyses. First, the stability characteristics in terms of stability modes were examined by creating a flight dynamics model of the studied airplane. Secondly the controllability of the vehicle was investigated by examining the control surfaces. It was found that the original design of the UAV was dynamically unstable and that the control surfaces were too large making the airplane di-cult to 　y in trim condition. By studying the stability characteristics of the simulated airplane it could be concluded that the UAV was dynamically stable for the improved design and thereby meet the requirements and recommendations.

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.