Searched for: subject%3A%22boundary%255C+layer%22
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Steinebach, Koen (author)
The wind energy industry is growing more than ever before and wind energy as a renewable energy source has shown quite a potential over the years. Unfortunately, the power yield of a wind farm can fluctuate largely over time, which originates from fluctuating wind speed magnitudes. Convection of air, turbulence, humidity and radiation of heat are...
bachelor thesis 2017
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Mertens, Christoph (author)
The boundary layer transition location is a crucial design parameter in aerodynamics. The computational prediction of boundary layer transition in engineering applications is typically based on empirical models. These models require experimental measurements for calibration and validation purposes. For unsteady aerodynamic processes, the range...
master thesis 2018
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Janssens, Martin (author)
Today's leading projections of climate change predicate on Atmospheric General Circulation Models (GCMs). Since the atmosphere consists of a staggering range of scales that impact global trends, but computational constraints prevent many of these scales from being directly represented in numerical simulations, GCMs require "parameterisations'' -...
master thesis 2019
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Munaro, Filippo (author)
In the context of the ongoing research regarding boundary layer transition, this project aims to study the effects of isolated cylindrical roughness elements on the transition from laminar to turbulent flow in a swept wing boundary layer. The project entails experimental campaigns: the 45 degrees swept wing model is placed inside the test...
master thesis 2017
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Lai, Yu-Jui (author)
This research studies the fluid-structure interaction (FSI) of compliant surfaces in air flows, with an objective of finding possible turbulent viscous drag reduction. A compliant surface is a thin layer of viscoelastic material drawing inspiration from dolphin epidermis, which was thought to have drag-reducing capabilities by Gray (1936)....
master thesis 2021
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Voogd, Alan (author)
This thesis experimentally assesses the benefit of Boundary Layer Ingestion (BLI) at the unaccelerated condition (thrust equals drag) of an integrated system in an industrial wind tunnel setting. The boundary layer or wake flow of the fuselage is ingested by the propulsor. Previous research shows that ingesting the boundary layer can lead to...
master thesis 2020
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Formidabile, Martina (author)
TOP contoured nozzles, with large area-ratios, are commonly employed in rocket propulsion systems as they feature an excellent thrust-to-weight ratio. A significant shortcoming to this design is that, during the startup and shutdown transients of a LRE, the internal nozzle flow progresses through a series of overexpanded flow states - Free Shock...
master thesis 2023
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van Wijk, Erwin (author)
To evaluate the performance of proposed submerged intakes in an early design phase, a performance analysis model able to evaluate a range of intake geometries is required. This document details how such a model was developed with the use of available sub-models for specific flow features. A formulation of the method of characteristics suitable...
master thesis 2017
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PENG, Yi-Kai (author)
Boundary Layer Ingestion (BLI) is a promising propulsion concept for aviation, aiming to reduce fuel burn. This configuration involves using the propulsor to ingest the boundary layer from the fuselage or wing. Typically, aircraft with BLI propulsors also integrate a hybrid-electric powertrain. This integrated setup has shown potential in fuel...
master thesis 2023
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Lambers, Tim (author)
Due to the growing energy demand and global warming renewable energy is currently of interest. To deal with the production intermittency of renewable energy, energy might be stored in hydrogen. Hydrogen can be converted into electricity with a fuel cell or by combusting hydrogen in a gas turbine. Gas turbines are more suitable for large power...
master thesis 2021
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ANAND, ABHIRATH (author)
The turbulent boundary layer development under the influence of an air cavity is studied experimentally using planar PIV, with the aim of gaining insight and building upon the flow physics typically encountered in the application of air layer drag reduction. A detection technique based on correlation values is implemented to obtain an...
master thesis 2021
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de Groot, Geiske (author)
The non-linear relation between Evapotranspiration (ET) and the atmospheric moisture demand in terms of vapor pressure deficit (VPD) has been widely reported. Observations point towards a diverse range of potential drivers; however, without uncovering why the identified factors are found to control diurnal ET-VPD hysteresis. Modelling efforts...
master thesis 2019
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Kerkvliet, M. (author)
In this thesis a numerical investigation was performed to increase our understanding of a low Reynolds number transition behind a zigzag trip. This was done with the use of Direct Numerically Simulation (DNS). This means that the Navier-Stokes equations are solved numerically without any use of a turbulence model. The DNS solver of the CFD...
master thesis 2011
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Stam, C.J. (author)
Vortex generators (VGs) are effectively used to improve the performance of the wind turbine blades by means of flow control. VGs can be represented by local geometrical disturbance on the aerodynamic surfaces. This disturbance generates vortices in the streamwise direction, energizing the boundary layer and hence delaying or suppressing the flow...
master thesis 2016
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Bink, J. (author)
Wind tunnels are used to study airflows around objects like cars, airplanes and ice-skaters. This is done, simulating the real world, by blowing an airflow over a fixed body. In the real situation an object moves through the air, while in a wind tunnel it is the air that is moving. So a wind tunnel needs to generate an airflow. In this airflow,...
master thesis 2008
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Van Dam, E.M. (author)
This thesis experimentally assesses the inflow towards the propulsors and the pressure distribution at the propulsor fan-face for the boundary layer ingesting D8 aircraft, and examines the dependence of the model, the propulsor and the flight condition on the inlet distortion. Use is made of mini-tuft flow visualization and five hole probe...
master thesis 2015
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Breedijk, Myrthe (author)
This study aims to look into the effect of small-scale surface heterogeneity on the mixing properties within the stable boundary layer (SBL) and the impact of different configurations of the heterogeneity on this mixing. The motivation for this research is to better understand the turbulent mixing phenomena in the SBL and to be able to represent...
master thesis 2021
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Topper, Friso (author)
Boundary layer ingestion is an airframe-propulsion integration technology capable of enhancing aircraft propulsive efficiency. The Propulsive Fuselage Concept, a tube-and-wing layout with an rear-fuselage-mounted propulsor in the boundary layer ingestion configuration, especially takes advantage this. However, the relation between physical shape...
master thesis 2023
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de Koning, Coert (author)
To achieve delay of laminar-to-turbulent transition of boundary layers, the application of acoustic metamaterial concepts is investigated. This is done analytically, numerically and experimentally by studying the interaction between a Helmholtz resonator and a TS wave. A Helmholtz resonator can serve as a meta-atom in a metamaterial. The desired...
master thesis 2021
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Jose, Nikhil (author)
Surfaces that induce slip at the wall have been shown to reduce skin friction drag in the turbulent regime. While superhydrophobic and liquid-infused surfaces are capable of drag reduction in turbulent hydrodynamic flows, neither would be feasible in aerodynamic applications due to the added roughness and the minuscule slip lengths created by...
master thesis 2023
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