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van der Mark, Luuk (author)
Current design methods for oblique manifolds were first presented in the paper of London et al. in 1968. This method presents a single equation to shape the dividing manifold of several manifold configurations. However, current literature shows a potential to improve the current design method by implementing advanced techniques. This paper aims...
master thesis 2024
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Algra, Hendrik Jaap (author)
The predominant influence of geometry and tensile stress on the Q factor of nanomechanical resonators is a phenomenon commonly described as dissipation dilution. In recent years, a variety of studies has looked into maximizing this effect, resulting in an assortment of softly-clamped resonator designs. This paper proposes a methodology that uses...
master thesis 2024
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Oudejans, Benjamin (author)
In this thesis, we derive a lower bound on a quantity appearing in a Fourier multiplier inequality on solvable Lie groups.<br/>In Caspers, Janssens, Krishnaswamy-Usha and Miaskiwskyi (2022), a classical result by de Leeuw about the restriction of Fourier multipliers on $\mathbb{R}^n$ to a discrete subgroup is extended to a noncommutative setting...
master thesis 2023
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van der Hulst, Robin (author)
To this date, simulating the dynamics of a fluid remain extremely expensive for most practical design prob- lems. The large range of length and time scales to be resolved makes it especially computationally heavy. In engineering applications, the standard is still the RANS approach for CFD modelling. Most commonly the so- called two-equation...
master thesis 2022
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Barara, Daamanjyot (author)
To cater to the increasing demand in short-range passenger air transport and the research in electric and hybrid aircraft, there is a renewed interest in the research of propellers. Propellers are known to have high aerodynamic efficiency, which translates to lower fuel burn in comparison to other jet engines, making it an attractive option for...
master thesis 2022
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Wiarda, Sjoerd (author)
In this thesis, we analyse the spectrum of the generator of the one-dimensional Zig-Zag process defined on the torus $\mathbb{T}$. This is a piecewise deterministic Markov process (PDMP) used in Monte Carlo Markov chain methods (MCMC) for sampling from a probability distribution and calculating integrals \cite{Rejectionfree}, \cite{ZigZag}, ...
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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Pasvanti, Nikoleta (author)
The demand for efficient lightweight structures grows rapidly in the aerospace sector. Topology optimization, introduced in the late 80s, is a method capable of producing such structures and has been mainly studied for isotropic materials. On the other hand, the performance of composite structures, which are already widely employed in the...
master thesis 2021
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van den Bos, Joshua (author)
In this thesis, a new methodology called the adjoint method is developed to select an optimal set of beam angles and beam weights in external beam radiotherapy. The Linear Boltzmann Transport Equation is specifically adjusted for proton transport and forms the Fokker-Planck approximation. The Fokker-Planck approximation models proton transport....
master thesis 2021
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Vos, Bart (author)
In recent years many automatic differentiable programming frameworks have been developed in which numerical programs can be differentiated through automatic differentiation (AD). Examples of these frameworks are Theano, TensorFlow and Pytorch. These frameworks are widely used in Machine Learning. AD also finds applications in the field of...
bachelor thesis 2021
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Geuens, C.S.E. (author)
Direct design optimisation methods for turbomachinery blades have consistently gained in popularity over time. This has been accomplished by significant advances in optimisation algorithms, and notably the development of adjoint-based gradient computation, which provides objective sensitivity information at comparatively low computational cost....
master thesis 2020
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Zijlker, Tammo (author)
This study aims to improve estimates of NOx emission strengths by assimilation of TROPOMI satellite retrievals in the LOTOS-EUROS chemical transport model. Nitrogen oxides (NO and NO2) play a pivotal role in atmospheric chemistry, are an important source of air pollution and contribute to nitrogen deposition over vulnerable natural areas....
master thesis 2020
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Gaens, Hendrik (author)
In the pursuit of a new ultra-efficient generation of turbomachines, novel and more sophisticated flow simulation and optimization methods have to be adopted. With the development of harmonic balance (HB) methods and adjoint optimization, questions arise on the concrete benefits of using one method over another. This research investigates the...
master thesis 2020
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Jagt, Declan (author)
Although a transition to more sustainable energy production is necessary, fossil fuels will remain a crucial contributor to the world's energy production in the near future. In numerically maximizing the production of these fuels, as well as in many other optimization problems, an objective function has to be optimized on the basis of an input...
master thesis 2020
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Latour, Marc (author)
Next-generation propulsion systems will likely take advantage of boundary layer ingestion (BLI), which requires simulation and design tools to perform optimization at an affordable cost while taking airframe interaction into account. A solution for this problem is the reduced-order body force model (BFM). It allows for computationally...
master thesis 2020
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Sanghera, Bhupinder Singh (author)
Prior to the detailed design of turbines, turbomachinery engineers must rely on mean-line and throughflow models to come to a preliminary design. These models are based on empirical loss correlations and are often derived from cascade experiments and numerical analyses that are confined to the subsonic and transonic regime. Axial turbines for...
master thesis 2020
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Garrido de la Serna, Pablo (author)
In order to reduce the carbon foot-print of turbo-generators to global warming, a step-change in the design process is needed. Extensive CFD simulations coupled with optimization algorithms are required, resorting to novel techniques to capture the complex flow phenomena occurring in the passage. However, the computation of the optimization...
master thesis 2019
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van den Brink, Robbert-Jan (author)
Mines and improvised explosive devices are the cause of many mortalities of vehicle occupants. Both experimental and numerical research in this field aims to improve the safety of military vehicles. TNO has advanced Finite Element (FE) models to simulate such events. The numerical research is done to better understand mine blasts. Another aim is...
master thesis 2019
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kleyn Winkel, Lars (author)
The goal of this project is to see if we can improve the treatment plan for proton therapy by using reduced order models and adjoint theory for proton therapy. We shall use a singular value decomposition on a dose distribution matrix to obtain the modes from which we can reconstruct every dose distribution. Using adjoint methodologies for proton...
bachelor thesis 2019
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Jonker, Hendrik (author)
Since the liberalization of the energy markets, the storage of energy is decoupled from the production and sales. In Western-Europe the storage of natural gas becomes more and more important because production fields get depleted and governments force companies to slow down their production because of tremors in the ground. Natural gas needs to...
master thesis 2019
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