Searched for: subject:"turbulence"
(1 - 20 of 99)

Pages

document
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
document
van Korlaar, Arent (author)
Turbulence closure models will continue to be necessary in order to perform computationally affordable simulations in the foreseeable future. It is expected that Reynolds-averaged Navier-Stokes (RANS) turbulence models will still be useful with the further development of the more accurate, but computationally expensive large eddy simulation (LES...
master thesis 2019
document
Maselis, Robbe (author)
Compressed natural gas (CNG) has been gaining attention in the automotive industry since it allows for a substantial reduction in carbon dioxide emissions. Recent advancements in direct-injection technology have contributed to an increase in volumetric efficiency and engine power, but the physical modeling of such gaseous injection with...
master thesis 2019
document
Pandey, Mayank (author)
The Beam Dump Facility (BDF) is a new fixed target facility proposed to be installed in the North Area of CERN. Currently in its design phase, the BDF is aimed at the Search for Hidden Particles (SHiP) experiment, which purpose is to investigate the origin of dark matter and other lightly interacting particles. The BDF target/dump sits at the...
master thesis 2018
document
Fatou Gomez, Javier (author)
The computation of complex turbulent flows design optimization processes is currently limited by the lack of accuracy of Reynolds-Averaged Navier-Stokes (RANS) in massively separated flows and the infeasible cost of multiple Large-Eddy Simulation (LES) evaluations. A novel method is presented, injecting data from LES or other high-fidelity...
master thesis 2018
document
Bhadra, Abhiroop (author)
Turbulence is a commonly encountered state of fluid dynamics. Unsteady turbulent flows in pipes are present in many engineering applications and also in biological flows. However, the various processes active in such flows are not well understood. The present work employs stereo-PIV to investigate the effects of a sinusoidal pressure gradient on...
master thesis 2018
document
Sridharan, Sudarshan (author)
The research in resolving the smaller scales of turbulence has gained significant attention in recent years, owing to the advancements in the measurement techniques. High resolution experimental studies are required to investigate high Reynolds number flows where the scales of turbulence are very small. This is of particular importance in...
master thesis 2018
document
Kroes, Jenske (author)
Subsea Rock Installation vessels cover pipelines, which transport oil from oil and gas fields. This is done by means of a flexible fallpipe until depths of 1000 meters. Around the Shetland Islands, the workability of the vessels at two specific project locations is compromised by the conditions in the ocean. In this research, data from a 3D...
master thesis 2018
document
Mandyam Chakravarthy, Akshar (author)
Laminar-turbulent transition (LTT) is the process through which smooth laminar flow transits into chaotic turbulent flow. Investigation of the paths taken to transit into turbulence is a front-runner among other methods followed to characterise turbulent flows. This is of particular importance in aerospace and energy industries for the design of...
master thesis 2018
document
Diez Sanhueza, Rafael (author)
Turbulence modelling corresponds to one of the greatest unsolved problems in physics and mathematics. This phenomenon is marked by the emergence of chaotic vortex structures in the solution of the Navier-Stokes equations, and it corresponds to the leading-order effect in the majority of the flows observed in nature. Due to the importance of...
master thesis 2018
document
Toutouh, Azeddine (author)
In 1949, Toms (Toms B.A., (1949, 1977)) observed that small amounts of a drag reducing agent (DRA) could cause a considerable drag reduction in turbulent pipe flow. In application of polymer enhanced oil recovery, degradation of polymers in the supply lead could cause clogging. It was, however observed that surfactants at sufficiently high...
master thesis 2018
document
Ruiter, Stijn (author)
Predicting the behavior of turbulent flows and how thermochemical properties develop such as temperature, enthalpy or concentrations is an import aspect in various fields. However, numerical calculations have a high time complexity. Therefore, models were constructed to approximate these flows. This thesis focuses on using probability density...
bachelor thesis 2018
document
Casacuberta Puig, Jordi (author)
Micro-ramps are passive flow control devices used to delay flow separation. Their use is widespread due to their reduced drag and structural robustness. We reproduce with Direct Numerical Simulations (DNS) recent Particle Image Velocimetry (PIV) experiments of the micro-ramp flow performed at TU Delft to study the wake of a micro-ramp immersed...
master thesis 2018
document
Mascini, Merlijn (author)
A turbulent flow is composed of swirling eddies of many sizes. Energy, which is added to the flow at the larger scales, is transferred down through consecutively smaller eddies until the scale is small enough that viscous forces dominate, at which point the energy is dissipated. The mechanism by which energy is transferred down the scales of...
bachelor thesis 2018
document
Stevens, Thieu (author)
In this thesis, it is studied if the stability of a stone in a granular bed protection, can be predicted by the local output of a three-dimensional (3D) eddy resolving simulation technique.

In earlier studies regarding stone stability, Reynolds-Averaged Navier-Stokes (RANS) models are used to determine the loads on the bed. In the...
master thesis 2018
document
Tierolff, Espen (author)
Currently, 54% of the general population lives in urban areas. This number is estimated to increase to 66% by 2050. Urbanization is generally linked to several phenomena that are detrimental to the overall quality of life; the urban heat island effect, and the decrease of air quality due to pollutants. The addition of vegetation to urban areas...
master thesis 2018
document
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
document
Hamraz, Ash (author)
In Pressurized Thermal Shock (PTS) applications, there is a co-existence of different flow regimes. The regimes can be divided in two main groups namely, dispersed two-phase flows and the separated two-phase flows having relatively larger interface. Simulating a two-phase flow itself is already a complex task. It gets even more complex when the flow...
master thesis 2018
document
Döpke, Max (author)
In this research a global-coefficient non-linear eddy viscosity model (NLEVM) is studied. This model stems from the inherent inability of the Boussinesq approximation to model anisotropy and therefore flow features such as: swirl, stream-line curvature and secondary motions (Lumley, 1970; Pope, 1975; Craft et al., 1996). The focus lies on the...
master thesis 2018
document
Sharma, Saurabh (author)
The nuclear technology is changing at a rapid pace driven by the quest for more powerful and safer nuclear power plants, as a consequence several structural components in a reactor are becoming larger and slender while working fluids have higher densities and velocities. These changes can often alter the dynamics of the interaction between the...
master thesis 2018
Searched for: subject:"turbulence"
(1 - 20 of 99)

Pages