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Kokee, Louis (author)Computational Fluid Dynamics based on RANS models remain the standard but suffer from high errors in complex flows. In particular, turbulent kinetic energy is over-produced in high strain rate regions, such as the near wake of wind turbine flows. Data-driven turbulence modelling methods aim to derive novel turbulence models with lower...master thesis 2021
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Alhaddad, S.M.S. (author)Underwater slope failure is a common problem in the fields of geotechnical, dredging and hydraulic engineering, posing a major risk to submerged infrastructure and flood defences along coasts, rivers, and lakes. The term ‘flow slide’ refers to a specific, complex failure mechanism of underwater slopes, which occurs when a substantial amount of...doctoral thesis 2021
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Jansson, F.R. (author), Edeling, Wouter (author), Attema, Jisk (author), Crommelin, Daan (author)In this study, we investigate uncertainties in a large eddy simulation of the atmosphere, employing modern uncertainty quantification methods that have hardly been used yet in this context. When analysing the uncertainty of model results, one can distinguish between uncertainty related to physical parameters whose values are not exactly known...journal article 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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Jansson, F.R. (author), van den Oord, Gijs (author), Pelupessy, Inti (author), Grönqvist, Johanna H. (author), Siebesma, A.P. (author), Crommelin, Daan (author)As a computationally attractive alternative for global large eddy simulations (LESs), we investigate the possibility of using comprehensive three-dimensional LESs as a superparameterization that can replace all traditional parameterizations of atmospheric processes that are currently used in global models. We present the technical design for...journal article 2019
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Mehta, D. (author), Zhang, Y. (author), van Zuijlen, A.H. (author), Bijl, H. (author)Despite advances in turbulence modelling, the Smagorinsky model remains a popular choice for large eddy simulation (LES) due to its simplicity and ease of use. The dissipation in turbulence energy that the model introduces, is proportional to the Smagorinsky constant, of which many different values have been proposed. These values have been...journal article 2019
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Xavier, Donnatella Germaine (author)This Masters thesis is a new perspective on Large Eddy Simulation. The capability of goal oriented model constrained optimization technique to generate stable reduced order models without any additional stabilization term or subgrid scale modelling has been demonstrated. The low dimensional projection modes sought by the optimization program...master thesis 2018
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Neggers, R.A.J. (author), Ackerman, Andrew S. (author), Angevine, W. M. (author), Bazile, Eric (author), Beau, I. (author), Blossey, P. N. (author), Boutle, I. A. (author), de Bruijn, C. (author), cheng, A (author), van der Dussen, J.J. (author), Fletcher, J. (author), Dal Gesso, S. (author), Jam, A. (author), Kawai, H (author), Cheedela, S. K. (author), Larson, V. E. (author), Lefebvre, Marie Pierre (author), Lock, A. P. (author), Meyer, N. R. (author), de Roode, S.R. (author), de Rooy, WC (author), Sandu, I (author), Xiao, H (author), Xu, K. M. (author)Results are presented of the GASS/EUCLIPSE single-column model intercomparison study on the subtropical marine low-level cloud transition. A central goal is to establish the performance of state-of-the-art boundary-layer schemes for weather and climate models for this cloud regime, using large-eddy simulations of the same scenes as a...journal article 2017
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Mehta, D. (author)This thesis concerns the industrial application of large eddy simulation to wind farm aerodynamics. Through a series of simple tests, it presents the pros and cons of using energy-conserving time integration and furthers the importance of a dissipation-free spatial discretisation. Finally, it demonstrates the capability of the Energy-Conserving...doctoral thesis 2016
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We propose a new definition of the length scale in an eddy-viscosity model for large-eddy simulations (LES). This formulation extends and generalizes a previous proposal [Piomelli, Rouhi and Geurts, Proc. ETMM10, 2014], in which the LES length scale was expressed in terms of the integral length-scale of turbulence determined by the flow...conference paper 2015
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De Wit, L. (author)3D CFD simulations, lab experiments and field measurements are used to get more understanding of the turbulent near field overflow dredging plume mixing. The focus has been on the most often used dredging vessel: a trailing suction hopper dredger (TSHD). Near field overflow dredging plume mixing is important because it determines the far field...doctoral thesis 2015
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Nabi, M. (author), De Vriend, H.J. (author), Mosselman, E. (author), Sloff, C.J. (author), Shimizu, Y. (author)We present a 3-D physics-based high-resolution modeling approach to the dynamics of underwater ripples and dunes. The flow is modeled by large eddy simulation on a Cartesian grid with local refinements. The sediment transport is modeled by computing pickup, transport over the bed, transport in the water column, and deposition of rigid spherical...journal article 2013
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Nabi, M. (author), De Vriend, H.J. (author), Mosselman, E. (author), Sloff, C.J. (author), Shimizu, Y. (author)The paper describes a numerical model for simulating sediment transport with eddy-resolving 3-D models. This sediment model consists of four submodels: pickup, transport over the bed, transport in the water column and deposition, all based on a turbulent flow model using large-eddy simulation. The sediment is considered as uniform rigid...journal article 2013
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Nabi, M. (author), De Vriend, H.J. (author), Mosselman, E. (author), Sloff, C.J. (author), Shimizu, Y. (author)We present a three-dimensional high-resolution hydrodynamic model for unsteady incompressible flow over an evolving bed topography. This is achieved by using a multilevel Cartesian grid technique that allows the grid to be refined in high-gradient regions and in the vicinity of the river bed. The grid can be locally refined and adapted to the...journal article 2012
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Heus, T. (author), Jonker, H.J.J. (author), Van den Akker, H.E.A. (author), Griffith, E.J. (author), Koutek, M. (author), Post, F.H. (author)In this study, a new method is developed to investigate the entire life cycle of shallow cumuli in large eddy simulations. Although trained observers have no problem in distinguishing the different life stages of a cloud, this process proves difficult to automate, because cloud-splitting and cloud-merging events complicate the distinction...journal article 2009
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Van 't Westende, J.M.C. (author)Annular-dispersed gas-liquid pipe-flows are commonly encountered in many industrial applications, and have already been studied for many decades. However, due to the great complexity of this type of flow, there are still many phenomena that are poorly understood. The aim of this thesis is to shed more light on some of these processes involving...doctoral thesis 2008
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Paul, S.C. (author), Paul, M.C. (author), Jones, W.P. (author)In this work we investigate turbulent non-premixed combustion, including species concentrations and temperature, in a model of 3D cylindrical combustor. Gaseous propane (C3H8) and preheated air with temperature of 773K are injected through the combustor inlet. A Large Eddy Simulation (LES) technique is applied to solve the governing equations of...conference paper 2006
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Travin, A.K. (author), Shur, M.L. (author), Spalart, P.R. (author), Strelets, M.K. (author)Adjustments are proposed of the Delayed Detached Eddy Simulation (DDES) approach to turbulence. They preserve the DDES capabilities particularly for natural DES uses, and resolve the mismatch of the logarithmic layers discovered earlier for the basic DES technique when used for Wall-Modelled Large-Eddy Simulation (WMLES) of attached flows. The...conference paper 2006
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Shishkin, A. (author), Wagner, C. (author)Large Eddy Simulations (LES) of incompressible turbulent flow around a wind turbine blade at a chord Reynolds number of 5000 are performed using high-order spectral/hp element method (SEM). The method and the early results of the simulations are presented. Some requirements with respect to mesh generation for the SEM concerning h- and p...conference paper 2006
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Borggaard, J. (author), Iliescu, T. (author)The boundary commutation error in large eddy simulation is studied numerically. It is shown that an accurate representation of the boundary commutation error has an important role in a reliable large eddy simulation of wall bounded flows. The numerical experiments in this paper are conducted for a 2D channel flow.conference paper 2006
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