Mimicking of Non-conservative Systems: Demonstration of a generalized method for applying the mimetic spectral element method to non-conservative systems

The mimetic spectral element method is a relatively young method in numerical solutions of partial differential equations and actions that describe physical systems. Its advantage is that it takes the geometrical structure of the problem into account which guarantees consistency of the numerical scheme and the conservation of relevant quantities...

Output Error Estimation for Unsteady Flows Using Reconstructed Solutions: Effect of Compression and Reconstruction of Unsteady CFD Data using Neural Networks and PODs on Error Estimates

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...

Site-specific load time series emulation of an offshore wind turbine using surrogate models

Considering the goals set by the international community, the implementation of new energy sources has to increase considerably in the next seven years. In this thesis, the focus is on the acceleration and improvement of the application of offshore wind turbines. The power produced using this technology should become 3.6 times more before the...

Impact of numerical configuration on wind farm blockage simulations

Wind farm interactions with the surrounding airflow leads to a reduction in velocity greater than the linear sum of single turbine inductions and is known as global or upstream blockage. The mechanisms and magnitude of global blockage effect are not yet fully understood. Models to simulate upstream blockage to improve efficiency estimates and...

A Validation Infrastructure for Non-Ideal Compressible Fluid Dynamics: with applications to ORC Turbines

The objective of this thesis was to further the validation effort on the SU2 flow solver for non-ideal compressible flows. To do so, an uncertainty quantification infrastructure based on the V&V20 validation standard was developed. To determine whether a model error was present, the different sources of uncertainty were combined and then...

Wind Farm Layout Optimisation Under Uncertainty Using Surrogate Models

This research aims to develop a method to create a wind farm layout that is robust against the uncertainty source, the inter-year variation of Weibull parameters and wind direction sector probabilities. A wind farm layout optimisation problem under uncertainty corresponds to optimisation under uncertainty (OUU), which is computationally...

Multi-Fidelity Aerodynamic and Aeroacoustic Sensitivity Study of Isolated Propellers

In the global search to more sustainable developments, research in the field of propeller propulsion systems is experiencing a renewed interest. The combination of efficiency and noise production is not studied as extensively as propeller efficiency alone in past studies. In this study, the relation between propeller noise and efficiency is...

Validation of the SU2 Flow Solver for Classical Non Ideal Compressible Fluid Dynamics

The validation of SU2 for modelling classical non-ideal compressible fluid dynamics will advance the research into efficient ORC turbomachinery design. This study determines the validity of the two-dimensional flow solver for predicting the isentropic expansion of Siloxane MM through a converging-diverging nozzle using...

Multi-point aerodynamic shape optimization for airfoils and wings at supersonic and subsonic regimes

The second-generation of supersonic civil transport has to match ambitious targets in terms of noise reduction and efficiency to become economically and environmentally viable. High-fidelity numerical optimization offers a powerful approach to address the complex trade-offs intrinsic to this novel configuration. Past and current research however...

A Machine Learning Approach to Unresolved-Scale Modeling for Burgers’ Equation

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...

fastFoam - An aero-servo-elastic wind turbine simulation method based on CFD

The current wind turbine design tools are based on aerodynamic simulations using blade element momentum (BEM) codes to calculate loads and power, see for instance the tools HAWC2, Bladed or FAST. This engineering method is computationally efficient, but theoretically valid only for steady two dimensional flow in non-yawed conditions. <br/><br/...

Numerical modelling of transcritical fluid behaviour using Lattice Boltzmann method

For the past fifty years, there has been a constant increase in the pressure ratio of gas turbines motivated by the need to increase the cycle efficiency. This has moved the operating pressure of gas turbine combustor to be above the critical pressure of jet fuels. This increasing trend in pressure of combustor, places the next generation gas...

Unconventional Propulsive Empennage - Future or Fiction?: Stability and control analysis and the effect of scaling of the DUUC

Flight testing is an activity that exists since the beginning of flight, and is still seen as an essential part of the aircraft development process. While numerical simulation has been improved significantly over the last decade, flight testing remains attractive in the exploration and evaluation of the flight envelope, especially in the region...