Enhanced TABS-MDS model for simulating large-scale free surface flows

2006 ◽  
Vol 21 (1) ◽  
pp. 98-106 ◽  
Author(s):  
Prasada Rao ◽  
Miguel A. Medina
Keyword(s):  
Free Surface ◽  
Large Scale ◽  
Free Surface Flows ◽  
Surface Flows ◽  
Scale Free

Advanced CFD Simulations of free-surface flows around modern sailing yachts using a newly developed openFOAM solver

2016 ◽  
Author(s):  
Janek Meyer ◽  
Hannes Renzsch ◽  
Kai Graf ◽  
Thomas Slawig
Keyword(s):  
Free Surface ◽  
Large Scale ◽  
Breaking Waves ◽  
Free Surface Flows ◽  
Body Motion ◽  
Computational Time ◽  
Efficient Computation ◽  
Surface Flows ◽  
Scale Free ◽  
Wide Range

While plain vanilla OpenFOAM has strong capabilities with regards to quite a few typical CFD-tasks, some problems actually require additional bespoke solvers and numerics for efficient computation of high-quality results. One of the fields requiring these additions is the computation of large-scale free-surface flows as found e.g. in naval architecture. This holds especially for the flow around typical modern yacht hulls, often planing, sometimes with surface-piercing appendages. Particular challenges include, but are not limited to, breaking waves, sharpness of interface, numerical ventilation (aka streaking) and a wide range of flow phenomenon scales. A new OF-based application including newly implemented discretization schemes, gradient computation and rigid body motion computation is described. In the following the new code will be validated against published experimental data; the effect on accuracy, computational time and solver stability will be shown by comparison to standard OF-solvers (interFoam / interDyMFoam) and Star CCM+. The code’s capabilities to simulate complex “real-world” flows are shown on a well-known racing yacht design.

scholarly journals Three-Dimensional Numerical Modeling of Large-Scale Free Surface Flows with Heat and Contaminant Transfer in Reservoirs

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Wei Diao ◽  
Hao Yuan ◽  
Liang Chen ◽  
Xujin Zhang ◽  
Cunze Zhang
Keyword(s):  
Free Surface ◽  
Large Scale ◽  
Three Dimensional ◽  
Coupling Model ◽  
Free Surface Flows ◽  
Surface Flows ◽  
Scale Free ◽  
Pollutant Distribution ◽  
Contaminant Transfer ◽  
Double Diffusive

The temperature distribution and pollutant distribution in large reservoirs have always been a hotspot in the field of hydraulics and environmentology, and the three-dimensional numerical modeling that can effectively simulate the interactions between the temperature fields, concentration fields, and flow fields needs to be proposed. The double-diffusive convection lattice Boltzmann method is coupled with a single-phase volume of fluid model for simulating heat and contaminant transfer in large-scale free surface flows. The coupling model is used to simulate the double-diffusive natural convection in a cubic cavity and the temperature distribution of a model reservoir. The mechanism of convection-diffusion, gravity sinking flow, and the complexity of the temperature and the pollutant redistribution process are analyzed. Good agreements between the simulated results and the reference data validate the accuracy and effectiveness of the proposed coupling model in studying free surface flows with heat and contaminant transfer. At last, the temporal and spatial variations of flow state, water temperature stratification, and pollutant transport in the up-reservoir of a pumped-storage power station are simulated and analyzed by the proposed model. The obtained variations of the flow field agree well with the observations in the physical model test and in practical engineering. In addition, the simulated temperature field and concentration field are also consistent with the general rules, which demonstrates the feasibility of the coupling model in simulating temperature and pollutant distribution problems in realistic reservoirs and shows its good prospects in engineering application.

Simulation of Gas-Liquid Free Surface Flows in a Refrigerant Distributor and a Nozzle of Continuous-Inkjet

2013 ◽  
Author(s):  
Masanori Ishikawa ◽  
Eiji Ishii ◽  
Masato Ikegawa
Keyword(s):  
Free Surface ◽  
Large Scale ◽  
Industrial Applications ◽  
Free Surface Flows ◽  
Liquid Column ◽  
Experimental Results ◽  
Surface Flows ◽  
Breakup Length ◽  
Liquid Free Surface ◽  
Simulation Results

A gas-liquid flow in the mm-μm scale is often used in industrial equipment, and it is necessary to develop prediction technology to determine the complicated behavior of a free surface transform. Open source CFD software, such as OpenFOAM, has recently attracted attention for use in industrial applications. We investigated the possibility of using OpenFOAM in the development process of fluid machinery products. We started out by conducting a continuous-inkjet simulation. We compared the simulation results for the breakup length of a liquid column with theoretical results, and then, we evaluated the effect of nozzle length on the breakup length of the liquid column. Next, we evaluated a refrigerant distributor by conducting another simulation. The simulated distribution ratio of the refrigerants was compared with the experimental results, and we checked the efficiency of a parallel simulation. The simulation results for each model qualitatively agreed well with the theoretical or experimental results. Therefore, we found that the simulation using OpenFOAM was effective for large scale simulation of gas-liquid free surface flows.

Modelling of Free Surface Flow Within the Two-Fluid Euler-Euler Framework

2015 ◽  
Author(s):  
Paul Porombka
Keyword(s):  
Free Surface ◽  
Large Scale ◽  
Flow Regimes ◽  
Free Surface Flows ◽  
Two Phase Flows ◽  
Two Phase ◽  
Surface Flows ◽  
Macro Scale ◽  
Interfacial Drag ◽  
Two Fluid

Two-phase flows are regularly involved in the heat and mass transfer of industrial processes. To ensure the safety and efficiency of such processes, accurate predictions of the flow field and phase distribution by means of Computational Fluid Dynamics (CFD) are required. Direct Numerical Simulations (DNS) of large-scale two-phase flow problems are not feasible due to the computational costs involved. Therefore the Euler-Euler framework is often employed for large-scale simulations which involves macro-scale modelling of the turbulent shear stress and the interphase momentum transfer. As a long term objective, the research activities at Helmholtz-Zentrum Dresden-Rossendorf (HZDR) pursue the development of general models for two-phase flows which are based on first principles and include less empiricism. Part of this effort is focused on the development of an algebraic interfacial area density model (AIAD) which enables the simulation of two-phase flows with general morphologies including bubble, droplet and stratified flow regimes with the two-fluid approach. In this work a short overview of the AIAD model is given and recent developments are presented. The modelling of the interfacial drag in free surface flows is of particular interest and subject to ongoing research. Apart from empirical correlations, which are limited to certain flow regimes, different models for the local calculation of the interfacial drag have been developed. The latter approach is followed in the AIAD model and has recently been subject to modifications which are presented and validated as a part of this study. Furthermore, special attention is paid to the turbulence treatment at the phase boundary of free surface flows. A general damping of the gas-side turbulent fluctuations in the near interface region has been described previously in the literature but has not yet found its way into eddy viscosity turbulence models. In this work, a previously proposed damping source term for the k-ω turbulence model is validated. Model validation is performed by comparing the simulation results to experimental data in case of stratified, countercurrent air-water flow in a closed channel.

scholarly journals Large-Scale Simulations for Free-Surface Flows with Objects by Lattice Boltzmann Method

2019 ◽  
Vol 33 (1) ◽  
pp. 55-62
Author(s):  
Seiya WATANABE ◽  
Takayuki AOKI ◽  
Yuta HASEGAWA ◽  
Jun KAWAHARA ◽  
Hirotada HASHIMOTO
Keyword(s):  
Free Surface ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Large Scale ◽  
Free Surface Flows ◽  
Surface Flows ◽  
Boltzmann Method ◽  
Large Scale Simulations

Large-scale turbulent structure of uniform shallow free-surface flows

2007 ◽  
Vol 7 (2) ◽  
pp. 159-172 ◽  
Author(s):  
V. Nikora ◽  
R. Nokes ◽  
W. Veale ◽  
M. Davidson ◽  
G. H. Jirka
Keyword(s):  
Free Surface ◽  
Large Scale ◽  
Free Surface Flows ◽  
Turbulent Structure ◽  
Surface Flows
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