http://hdl.handle.net/2268.2/5 Thu, 05 Mar 2026 10:37:42 GMT 2026-03-05T10:37:42Z http://hdl.handle.net/2268.2/25235 Title: Topology optimization of Oil tank supports Abstract: Reducing structural mass while maintaining mechanical integrity is a key objective in the aeronautical industry, as it directly contributes to improved efficiency and reduced emissions. In this context, the present work investigates the application of topology optimization to an aircraft engine oil tank support system, intending to achieve mass reduction while ensuring rigorous structural performance under combined static and dynamic loading conditions. The support system consists of three main components—triangles, lugs, and brackets—and is analyzed within an industrial framework using ANSYS Mechanical. Since topology optimization in ANSYS is restricted to static loading formulations, dynamic effects are addressed through subsequent modal and harmonic analyses performed for validation purposes. The methodology combines static, modal, and harmonic reference analyses with multiple topology optimization studies, focusing on the influence of design-space definition, mesh resolution, retained mass limits, stress constraints, and projection parameters. The results demonstrate that the optimization outcome is strongly governed by the size and stiffness of the design space, mesh density, and the interaction between optimized and non-optimized regions. Sensitivity analyses highlight the importance of appropriate parameter selection to obtain stable and physically meaningful topologies. Among the investigated formulations, compliance minimization combined with stress and mass constraints provides the most consistent and robust results across different configurations. Validation under static and dynamic loading confirms the relevance of the optimized designs, while also revealing limitations related to mesh dependency and load-path sensitivity. Overall, this study illustrates both the potential and the limitations of industrial topology optimization workflows applied to complex structures. It provides practical insights and guidelines for the effective use of topology optimization as a design-support tool rather than a direct geometry-generation method. Thu, 22 Jan 2026 23:00:00 GMT http://hdl.handle.net/2268.2/25235 2026-01-22T23:00:00Z http://hdl.handle.net/2268.2/25233 Title: Development of Physical Models for Launch Vehicle Dynamics Simulation Abstract: This thesis presents the development and integration of a set of physical models for launch vehicle dynamics simulation within an existing simulation framework used at Spacebel. The work focuses on improving the representation of the physical environment and the associated forces acting on the vehicle, with particular emphasis on atmosphere, aerodynamics, and gravity. A modular modeling approach is adopted, in which new environment and force computation blocks are implemented and coupled with the vehicle dynamics. The developments include the implementation of an atmospheric model with stochastic turbulence based on the Dryden formulation, the computation of aerodynamic angles and loads, and improvements in the handling of kinematics, reference frames, attitude dynamics, and gravity modeling. The implemented models are verified through unit tests and consistency checks in order to ensure their physical validity and numerical robustness. In a second step, the impact of atmospheric disturbances on the vehicle response is investigated. Deterministic sensitivity analyses are first carried out to assess the influence of key parameters such as turbulence intensity and mean wind magnitude. Then, Monte Carlo simulations are performed to quantify the statistical dispersion of critical aerodynamic quantities, including the angle of attack, sideslip angle, dynamic pressure, and lateral aerodynamic force. The results show that the turbulence intensity mainly affects fluctuation-related metrics, while steady wind components and stochastic realizations can significantly modify the flight conditions at which peak loads occur. In particular, lateral aerodynamic quantities exhibit a very large variability across realizations, and rare but more severe cases are observed. These results highlight the strongly nonlinear nature of the coupled atmosphere--aerodynamics--dynamics system. Overall, this work provides a consistent extension of Spacebel's simulation framework and demonstrates its capability to support physically sound modeling and uncertainty-aware analyses for launch vehicle dynamics simulation. Thu, 22 Jan 2026 23:00:00 GMT http://hdl.handle.net/2268.2/25233 2026-01-22T23:00:00Z http://hdl.handle.net/2268.2/25228 Title: Master's thesis and Internship : Thermal modelling and experimental measures of a French-type masonry stove for Low-Tech heating applications Abstract: This thesis supports the Renolow project of the non-profit organisation LowTech Liège, which promotes low-tech renovation strategies, by focusing on a French-type masonry stove used for household heating. To help the association in their goal of spreading this heating system, a transient numerical model of the stove’s thermal behaviour is developed. This model can be used by LowTech Liège as a tool to evaluate temperature evolution, thermal comfort, and energy use quantitatively. The numerical model is implemented in Python and relies on a discretised representation of the stove. The model is separated in two parts: a representation of the time-varying heat released by batch wood combustion, and the heat transfer processes described through a resistance–capacitance (RC) network. Experimental temperature measurements from two test campaigns are used both to explore model parameters and to assess the validity of the simulations. The comparison with experimental data shows that the model captures the main transient thermal behaviour of the masonry stove, with simulated temperature profiles closely matching the experimental trends. The absolute root means square error, between simulated and experimental external wall surface temperatures is approximately 8 °C, corresponding to a mean absolute error of about 6.5 °C. Given the experimental uncertainties, the external surface temperatures ranging from 20 °C to about 130 °C, and the modelling assumptions, this level of agreement is considered satisfactory for a first-generation numerical model and provides a solid basis for further research and future thermal comfort and energy performance assessments. Thu, 22 Jan 2026 23:00:00 GMT http://hdl.handle.net/2268.2/25228 2026-01-22T23:00:00Z http://hdl.handle.net/2268.2/25227 Title: Travail de fin d'études / Projet de fin d'études : Évaluation du risque de surchauffe d'une maison QZEN et du potentiel de la ventilation naturelle nocturne et de la masse thermique : Un cas d'étude wallon Abstract: L’amélioration de la performance énergétique des bâtiments résidentiels a permis de réduire significativement les besoins de chauffage. Parallèlement, le risque de surchauffe estivale a considérablement crû et reste sous-évalué par les outils de simulation quasi-statique, historiquement orientés vers la demande de chauffage. Dans un contexte de changement climatique, cette problématique devient particulièrement critique pour les logements hautement isolés et étanches en Belgique, où les stratégies de refroidissement passif sont à privilégier par rapport aux systèmes actifs. Ce travail vise à évaluer le risque de surchauffe et le bilan énergétique d’une maison unifamiliale située en Wallonie. Les objectifs sont multiples : i) quantifier le risque de surchauffe à l’aide de simulations dynamiques et d’indicateurs de performance reconnus, ii) évaluer le potentiel de la ventilation naturelle nocturne et de l’augmentation de l’inertie thermique quotidienne comme stratégies passives d’atténuation, iii) analyser le bilan énergétique QZEN du bâtiment, incluant son interaction avec le réseau électrique et l’impact potentiel d’une batterie de stockage. La méthodologie repose sur des simulations dynamiques réalisées avec le logiciel TRNSYS, sur base d’un pas de temps horaire. Le risque de surchauffe est évalué à l’aide des indicateurs Indoor Overheating Degree (IOD) et Ambient Warmness Degree (AWD), appliqués selon des critères de confort thermique fixes et adaptatifs. Plusieurs scénarios sont étudiés, intégrant différents débits de ventilation, plusieurs niveaux d’inertie contrastés, ainsi que des projections climatiques futures issues du modèle climatique régional MAR selon les scénarios SSP3-7.0 et SSP5-8.5. Les résultats montrent que la ventilation naturelle nocturne constitue une stratégie passive très efficace, d’un potentiel actuel de 86% selon le modèle confort considéré, et que l’augmentation de la masse thermique apporte un effet modéré mais complémentaire. Toutefois, l’impact des conditions extérieures sur la surchauffe du bâtiment demeure fort élevé dans les scénarios climatiques futurs et témoigne du manque de résilience des bâtiments QZEN. L’analyse du bilan énergétique met en évidence le décalage temporel important entre production photovoltaïque et demande électrique, partiellement atténué par l’intégration d’une batterie.; The improvement of the energy performance of residential buildings has led to a significant reduction in heating demand. At the same time, summer overheating risk has increased considerably and remains inaccurately addressed by quasi-static simulation tools, which were historically designed with a primary focus on heating needs. In the context of climate change, this issue becomes particularly critical for highly insulated and airtight dwellings in Belgium, where passive cooling strategies should be preferred over active systems. This study aims to assess the overheating risk and the energy balance of a single-family dwelling located in Wallonia. We have several objectives: (i) to quantify overheating risk using dynamic simulations and recognized performance indicators, (ii) to evaluate the potential of nocturnal natural ventilation and increased daily thermal inertia as passive mitigation strategies, and (iii) to analyze the building’s Q-ZEN energy balance, with particular attention to its interaction with the electricity grid and the potential contribution of battery storage. The methodology is based on hourly dynamic simulations performed with TRNSYS software. Overheating risk is assessed using the Indoor Overheating Degree (IOD) and Ambient Warmness Degree (AWD) indicators, applied under both fixed and adaptive thermal comfort criteria. Several scenarios are investigated, including varying ventilation rates, contrasted levels of thermal mass, and future climate projections derived from the regional climate model MAR under the SSP3-7.0 and SSP5-8.5 scenarios. The results show that nocturnal natural ventilation is a highly effective passive cooling strategy, with a current mitigation potential of up to 86% depending on the comfort model considered. Increasing thermal mass provides a more moderate but complementary effect. However, the influence of external climatic conditions on building overheating remains very strong under future climate scenarios, highlighting the limited resilience of Q-ZEN buildings. The energy balance analysis reveals a significant temporal mismatch between photovoltaic electricity production and building demand, which can be partially mitigated through the integration of battery storage. Thu, 22 Jan 2026 23:00:00 GMT http://hdl.handle.net/2268.2/25227 2026-01-22T23:00:00Z