http://hdl.handle.net/2268.2/1029 Tue, 08 Sep 2026 06:04:20 GMT 2026-09-08T06:04:20Z http://hdl.handle.net/2268.2/2295 Title: Development of an efficient 3D radiation transfer solver for atmospheric entry flows Abstract: Spacecraft undergo severe convective and radiative heating from the surrounding aerothermodynamic environment during their atmospheric entry at high velocities. An accurate heat-flux prediction during the design of such vehicles is therefore paramount for the success and safety of future planetary missions. The numerical simulation of hypersonic reactive plasma flows coupled with radiative heat transfer is an active research topic for the design of thermal protection systems of future space missions, in particular for the Mars exploration program. The numerical simulation of radiative transfer is a challenging problem because of the spatial, angular, and spectral dependence of the radiation field. The reference approach for treating the spectral dependence is the Line-By-Line (LBL) method which consists in finely discretizing the radiative properties over the relevant spectral range. These radiative properties depend on level populations and on fundamental spectroscopic data. We propose to implement a statistical narrow band formulation into the finite-volume algorithm for radiative heat-transfer of the COOLFuiD platform to decrease the computational time. 3D radiation fields will be computed for atmospheric entries of space missions. This work is related to the ABLARADABLA project of the European Space Agency. Thu, 26 Jan 2017 23:00:00 GMT http://hdl.handle.net/2268.2/2295 2017-01-26T23:00:00Z http://hdl.handle.net/2268.2/2291 Title: Model Correlation and Nonlinearities Detection On The EUI Instrument Aboard Solar Orbiter Spacecraft Abstract: The main objective of this project is to update the original FEM model used for the prediction of the structural dynamic behavior of the Qualification Model of the EUI-HRI Doors mechanism that will be mounted on the Solar Orbiter Spacecraft. The purpose of this updating is to correlate the FEM model so it can represent with higher accuracy the physical model. The original FEM model of the EUI-HRI Doors was created in SAMCEF and this same software will be used to update the complete model. Modal Assurance Criteria (MAC) and other techniques based on modal parameters will be used for the model updating.Moreover, an introduction to the nonlinear behavior of this instrument will be studied through different nonlinear detection methods. Principal Component Analysis will be used based on the literature. For this purpose, dynamic vibration data has been acquired at the Centre Spatial de Liège and it will be used for the model correlation and the nonlinear analysis. This project also intends to describe the process followed for the dynamic testing of a spacecraft instrument and how it is related to the verification and validation of the results. Thu, 26 Jan 2017 23:00:00 GMT http://hdl.handle.net/2268.2/2291 2017-01-26T23:00:00Z http://hdl.handle.net/2268.2/1661 Title: Trajectory optimisation of asteroids billiard Abstract: Since 2005, the Global Trajectory Optimisation Competition, GTOC, has taken place almost every year. Over time, its popularity has grown amongst the aerospace community and prestigious institutions like NASA or the ESA actually participated to this competition. The goal is always the same: the design of a interplanetary trajectory. The problem is, each time, nearly impossible to solve and every solution proposed by the teams composed a huge database. All those solution could of course be used in the future for scientific missions. This thesis will take an interest at the fourth edition of the competition called: "Asteroids Billiard". For this mission, a list of Near Earth Asteroids, NEA, is provided and the goal is, starting from the Earth, to flyby as many asteroids as possible before performing a rendezvous with a last one. The design of this trajectory is based on solving Lambert's problem between asteroids and choosing the trajectory that minimizes the fuel consumption. The more trajectories are computed, the more our search can be focus on long chains thanks to the analysis of those first trajectories. Wed, 07 Sep 2016 22:00:00 GMT http://hdl.handle.net/2268.2/1661 2016-09-07T22:00:00Z http://hdl.handle.net/2268.2/1659 Title: Capability study of a laser equipped balancing machine and algorithm development for assessing tire geometrical non uniformities Abstract: Tires are highly engineered products which have to be designed to meet several performances such as ride, handling, traction, etc. Tire subjective evaluation is still the key criteria to get an original equipment manufacturers approval. For this subjective evaluation, it is essential to select assemblies with best uniformities in order to avoid vibrations which could disturb the driver during its subjective assessment. New generations of balancing ma- chines provide capabilities to measure geometrical uniformity. The main goal of this thesis is to assess the measurement capabilities of such a laser equipped machine. This machine is going to be used for quick selection of best uniformity assemblies. For this purpose, measurements of this machine are compared to the measurements of another reference ma- chine. A feasibility study is conducted in this report in order to frame a robust comparison method between the two machines. The second goal of the project is the development of several indicators in order to correctly describe the uniformity of assemblies based on laser measurements. These indicators are extracted directly from the tire con- tour which is obtained after a test on the machine. Speci cally, one of the objective is to develop an algorithm in order to evaluate the lateral tread shift. Wed, 07 Sep 2016 22:00:00 GMT http://hdl.handle.net/2268.2/1659 2016-09-07T22:00:00Z