Searched for: subject%3A%22VOF%22
(1 - 18 of 18)
document
Chang, X. (author), Wellens, P.R. (author)
The lack of suitable boundary conditions in practical surface wave simulations with maritime structures in current or at forward speed may cause energy in the computational domain to accumulate due to spurious wave reflection. The common way to prevent wave reflection is to use passive wave absorbers, such as damping zones or relaxation zones...
journal article 2024
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Holkema, K. J. (author), Aalbers, C. (author), Wellens, P.R. (author)
In head waves, water jet impacts due to run up can occur as a result of the structural configuration of some floating structures, reducing workability. Wave attenuation near the floater may reduce the risk of water jet impacts. This paper presents a numerical study of the performance and attenuation mechanisms of various plate type fixed free...
journal article 2023
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Wellens, P.R. (author), Borsboom, Mart (author)
The boundaries of numerical domains for free-surface wave simulations with marine structures generate spurious wave reflection if no special measures are taken to prevent it. The common way to prevent reflection is to use dissipation zones at the cost of increased computational effort. On many occasions, the size of the dissipation area is...
journal article 2020
document
Sprong, Geert (author)
The bulbous bow is a common feature for large displacement vessels. The purpose of the bulbous bow is to reduce the bow wave, hereby making use of wave cancellation theory. The main drawback of these type of bows is that the drag reduction effect is only present for a limited range of sailing speeds. If the transit velocity is altered, the...
master thesis 2019
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Sigalas, Nikos (author)
In the present study the stability of crown wall elements on top of a rubble mound breakwaters is investigated. The first step was conducting a literature review, in order to identify knowledge gaps. It was found that current design methods do not take the freeboard of the crown wall into account when calculating the vertical force acting on it....
master thesis 2019
document
Spaans, Erik (author)
The accurate approximation of the surface tension force is paramount for continuum surface models in the field of computational fluid dynamics for multiphase flow where surface tension is relevant. This involves being able to accurately calculate the curvature at the interface. This study focuses on the use of convolution in smoothing the VOF...
bachelor thesis 2018
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Oud, G.T. (author)
This research entails the numerical simulation of physical flow instabilities that can occur in two-phase pipe flows with a new efficient algorithm. The fluids are assumed to be immiscible, and the flow is incompressible and isothermal in a straight circular pipe section with a certain inclination. The numerical algorithm that was developed...
doctoral thesis 2017
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Patel, H.V. (author), Das, S. (author), Kuipers, J.A.M. (author), Padding, J.T. (author), Peters, E.A.J.F. (author)
journal article 2017
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Duz, B. (author), Borsboom, M.J.A. (author), Veldman, A.E.P. (author), Wellens, P.R. (author), Huijsmans, R.H.M. (author)
In this paper the attention is focused on the effect of various VOF methods on efficient and accurate simulation of free surface water waves. For this purpose, we will compare several VOF methods in numerical simulations of propagating waves where strong nonlinear behavior is dominant in the flow. Comparisons and discussions will be provided to...
conference paper 2016
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Van der Neut, E.M. (author)
When designing a rubble mound breakwater, one would like to predict the stability of the armour layer of the breakwater. For this purpose several armour layer stability formula are developed. The most reliable is considered to be the stability formula of Van der Meer (1988). With this method, the armour layer stability is predicted based on...
master thesis 2015
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Lavies, H.G. (author)
The breakwaters of IJmuiden are of a unique design; a riprap core is covered with a thick impermeable asphalt slab. During construction and after completion, slope instability caused extensive damage. Placement of a concrete cube armour layer prevented further damage to the asphalt, but proved to be unstable and required a significant amount of...
master thesis 2014
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Van den Bos, J. (author), Verhagen, H.J. (author), Zijlema, M. (author), Mellink, B. (author)
A more detailed understanding of porous flow inside a rubble-mound structure may have potential benefits in breakwater design. Numerical models are expected to be a useful additional research tool in this field, provided that their calculation results can be validated against measurements. This paper presents the results of a systematic effort...
conference paper 2014
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Wellens, P.R. (author)
<Subject and main objective> There is a desire to assess extreme wave loads on offshore structures like Floating Production, Storage and Offloading (FPSO) vessels, either for design, or for evaluation when circumstances near the structure change. Design formulae for extreme wave loads are scarce and have limited validity for specific structures....
doctoral thesis 2012
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Luppes, R. (author), Duz, B. (author), Van der Heiden, H.J.L. (author), Van der Plas, P. (author), Veldman, A.E.P. (author)
The simulation tool ComFLOW, developed for accurate predictions of hydrodynamic wave loading, is based on the Navier-Stokes equations. The free-surface dynamics is described through VOF, with local height-function approach to enhance accuracy. Numerical reflections are prevented by specially designed absorbing boundary conditions. Gravity...
conference paper 2011
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Van den Bosch, I.C. (author)
Wave fields in the close vicinity of a coastal structure can be very complex, this is especially the case during extreme storm conditions and for complex geometries. There is a growing interest for numerical simulation tools capable of predicting in detail the complex hydrodynamic loads due to waves and currents and its effect at structures. In...
master thesis 2010
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De Baar, J.H.S. (author)
The keel of a sailing yacht has been shown to constitute a significant part of the overall resistance. Where the details of this effect are not yet fully understood, Computational Fluid Dynamics (CFD) analysis might reveal mechanisms unseen to the experimental eye. An important step in CFD application is the simulation of a number of validation...
master thesis 2010
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Lara, J.L. (author)
Adaptation of COBRAS VOF model for typical breakwater applications and worked out examples of water movement in and around breakwater cross sections.
report 2005
document
Losada, I.J. (author), Garcia, N. (author), Lara, J.L. (author)
Development and calibration of a volume averaging RANSmodel and corresponding k-epsilon equations. Calibration is done with 2DV flume tests.
report 2003
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