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Klaessen, Alexander (author)
There is a need to examine the potential of alternative methods such as Variational Multiscale Method (VMM) for the ability to improve the efficiency of combustion simulations. However the computational expense of a LES run of a 3D turbulent non-premixed combustion problem is high due to the large variety of length and time scales in turbulent...
master thesis 2023
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Sitaram, Arnish (author)
Unsteady numerical simulation has been proven to be an essential tool for research. The quality of the results can be improved by using mesh adaptation. Mesh adaptation uses error indicators to refine the mesh in regions with high errors. The error indicators used are output errors with the most accurate output error estimation method being...
master thesis 2023
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Bettini, Andrea (author)
This thesis presents an energy-conservative data-driven approach in modelling the closure terms of the Navier-Stokes equations casted through the Variational Multiscale (VMS) framework. For context, the VMS framework is applied in designing stabilised finite element methods for multiscale phenomena in which stability is not guaranteed. Under...
master thesis 2023
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Tluk, Alexander (author)
This research investigates the formation, growth, and size distribution of H2SO4 aerosols in aircraft engine plumes. It aims to enhance calculations by incorporating spatial variation and turbulence modeling. The study develops a toolchain using AER 3-D software, sets up a CFD model of an engine wake, and couples it with microphysics and...
master thesis 2023
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Kanala, Mohith (author)
master thesis 2023
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Blomme, Arthur (author)
Stratospheric Aerosol Injection (SAI) is a geoengineering method to mitigate the effects of increased greenhouse gas concentrations in the Earth’s atmosphere, and to prevent further global warming. SAI does not reverse climate change, it merely counteracts its symptoms by offsetting the radiative forcing of greenhouse gases, and it should be...
master thesis 2023
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Soliman, Elrawy (author)
Hybrid RANS-LES methods have become a popular numerical approach for a wide variety of flows. This is due to dissatisfaction with the RANS modelling paradigm in separated flows along with the prohibitive computational cost of pure LES, especially in wall-bounded flows at high Reynolds numbers. However, these methods are susceptible to the grey...
master thesis 2023
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Wegener, Malte (author)
Reconstructed Discontinuous Galerkin (rDG) methods aim to provide a unified framework between Discontinuous Galerkin (DG) and finite volume (FV) methods. This unification leads to a new family of spatial discretization schemes from order three upwards. The first of these new schemes is the rDG(P1P2) method, which represents the solution on each...
master thesis 2022
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Catalani, Giovanni (author)
Advancements in aircraft performance require increasingly complex design processes and tools. Simulating the unsteady non-linear aerodynamic interaction between a maneuvering aircraft and the surrounding flowfield poses serious challenges. High-Fidelity Computational Fluid Dynamics (CFD) methods, based on the numerical solution of the Navier...
master thesis 2022
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Shrestha, Suyash (author)
Structure-preserving or mimetic discretisations are a class of advanced discretisation techniques derived by employing concepts from differential geometry. Such techniques can attain specific conservation properties at the discrete level such as conservation of mass, kinetic energy, etc when applied to conservation laws. However, like...
master thesis 2022
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Toledo Farrando, Oscar (author)
Reduced-order models (ROMs) are commonly used to reduce the complexity of large-scale fluid dynamics problems. The main technique to obtain their basis is proper orthogonal decomposition (POD), where an energy-based basis is obtained. Such a basis is derived without considering the governing equations. Moreover, if the flow dynamics are not...
master thesis 2022
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Sahu, Sidhartha (author)
Vortex generators (VGs) are typically about two orders of magnitude smaller than their host component (such as an airplane wing). For this reason, conducting a fully-resolved RANS simulation to isolate their impact on the flow field is computationally expensive. This work presents a goal-oriented adjoint-based approach to model vortex generators...
master thesis 2022
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Millan Valbuena, Enrique (author)
We present a reduced order model (ROM) for a one-dimensional nonlinear gas dynamics problem: the isentropic piston. The main body of the PDE, the geometrical definition of the mesh nodes, and the boundary conditions are parametrized. The full order model is obtained with a Galerkin finite element discretization, under the Arbitrary Lagrangian...
master thesis 2021
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Bourier, Sébastien (author)
Evaluation of aircraft performance for design, certification, and maintenance purposes requires aerodynamic knowledge for the entire flight envelope of an aircraft. Simplified models that relate geometric properties and flight conditions of an aircraft to its aerodynamic properties are simply not sufficient anymore, as non-linear aerodynamic...
master thesis 2021
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Blom, Peter (author)
Research into constructing reduced-order models (ROM) to reduce computational cost or to interpret complex datasets from numerical or experimental sources has steadily been gaining popularity over the past few years. Many methods currently exist to construct ROMs. The proper orthogonal decomposition (POD) is one of the most widely adopted...
master thesis 2021
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Hunter, Thomas (author)
Numerical simulations and optimisation methods, such as mesh adaptation, rely on the accurate and inexpensive use of error estimation methods. Output-error estimation is the most accurate method; however, it relies on the use of approximations in order to be implemented in practice. The proposed method in this thesis relies on the use of super...
master thesis 2021
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Rajampeta, Sharath (author)
The use of Large Eddy Simulations(LES) in industry is steadily increasing as the complexity of the problems are increasing. However there remains a potential for significant improvements in LES. The Variational Multiscale Method(VMM) introduced by Hughes et al. (1998) provides a more consistent framework for turbulence modelling. The use of an...
master thesis 2021
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Robijns, Michel (author)
This thesis is part of a greater effort to use machine learning for the development of flexible and universal unresolved-scale models in large eddy simulation (LES). The novelty in the current work is that a neural network learns to predict the integral forms of the unresolved-scale terms directly without a priori assumptions on the underlying...
master thesis 2019
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Gnanasundaram, Arun (author)
The whole construct of explicit algebraic Reynolds stress models, as they are known in RANS, is based on the weak equilibrium assumption. By employing this assumption, and in addition, incorporating models for terms in the Reynolds stress transport equations, the system of six partial differential equations can be simplified to an algebraic form...
master thesis 2018
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Khajehzadeh, Arash (author)
This project aims to investigate propeller wing interaction of an over the wing (OTW) based distributed propulsion (DP) system with the addition of a secondary wing. This research explored the opportunities that OTW configuration provides to DP concept, such as improving the lifting performance of system by inducing the flow over the upper...
master thesis 2018
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