scholarly journals Numerical Simulation on Interface Evolution and Impact of Flooding Flow

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
J. Hu ◽  
Z. Q. Lu ◽  
X. Y. Kan ◽  
S. L. Sun
Keyword(s):  
Flow Model ◽  
Numerical Solutions ◽  
Navier Stokes ◽  
Navier Stokes Equation ◽  
Interface Evolution ◽  
Interface Capturing ◽  
Liquid Body ◽  
Upwind Discretization ◽  
Volume Method ◽  
Laminar Flow Model

A numerical model based on Navier-Stokes equation is developed to simulate the interface evolution of flooding flows. The two-dimensional fluid domain is discretised by structured rectangular elements according to finite volume method (FVM). The interface between air and liquid is captured through compressive interface capturing scheme for arbitrary meshes (CICSAM) based on the idea of volume of fluid (VOF). semiimplicit method for pressure linked equations (SIMPLE) scheme is used for the pressure-velocity coupling. A second order upwind discretization scheme is applied for the momentum equations. Both laminar flow model and turbulent flow model have been studied and the results have been compared. Previous experiments and other numerical solutions are employed to verify the present results on a single flooding liquid body. Then the simulation is extended to two colliding flooding liquid bodies. The impacting force of the flooding flow on an obstacle has been also analyzed. The present results show a favourable agreement with those by previous simulations and experiments.

scholarly journals Navier-Stokes Equation and Computational Scheme for Non-Newtonian Debris Flow

2014 ◽  
Vol 2014 ◽  
pp. 1-5
Author(s):  
Ignazio Licata ◽  
Elmo Benedetto
Keyword(s):  
Debris Flow ◽  
Flow Model ◽  
Computational Approach ◽  
Computational Scheme ◽  
Navier Stokes ◽  
Uniform Motion ◽  
Geological Data ◽  
Navier Stokes Equation ◽  
Grid Systems ◽  
Computing Effort

This paper proposes a computational approach to debris flow model. In recent years, the theoretical activity on the classical Herschel-Bulkley model (1926) has been very intense, but it was in the early 80s that the opportunity to explore the computational model has enabled considerable progress in identifying the subclasses of applicability of different sets of boundary conditions and their approximations. Here we investigate analytically the problem of the simulation of uniform motion for heterogeneous debris flow laterally confined taking into account mainly the geological data and methodological suggestions derived from simulation with cellular automata and grid systems, in order to propose a computational scheme able to operate a compromise between “global” predictive capacities and computing effort.

CUDA Based Numerical Simulation of Cavity Flow and Performance Analysis

2013 ◽  
Vol 291-294 ◽  
pp. 1954-1957
Author(s):  
Xiao Ping Li ◽  
Hong Ming Zhang
Keyword(s):  
Stokes Equations ◽  
Cavity Flow ◽  
Navier Stokes ◽  
Navier Stokes Equations ◽  
Floating Point Arithmetic ◽  
Upwind Discretization ◽  
C Program ◽  
And Performance ◽  
Volume Method ◽  
Point Arithmetic

Cuda has been widely used in computational fluid dynamics due to the powerful abilities of floating point arithmetic on gpu.This paper solved the Navier-Stokes equations of two dimensional incompressible flow using parallel programming on cuda. The finite volume method and the second-order upwind discretization scheme were used in the simulation.The speed of serial c program and the cuda based program were compared and we also compared the two programs on different hardware.The simulations got high precision results,which showed that the cuda based parallel computing is much more efficiency,and the parallel algorithm could get a more than 10 times the acceleration.

A two-dimensional vortex condensate at high Reynolds number

2013 ◽  
Vol 715 ◽  
pp. 359-388 ◽  
Author(s):  
Basile Gallet ◽  
William R. Young
Keyword(s):  
Stokes Equation ◽  
Numerical Solutions ◽  
Reynolds Numbers ◽  
Navier Stokes ◽  
Finite Limit ◽  
Two Dimensional ◽  
Navier Stokes Equation ◽  
Quasilinear Theory ◽  
Zero Integral ◽  
High Reynolds

AbstractWe investigate solutions of the two-dimensional Navier–Stokes equation in a $\lrm{\pi} \ensuremath{\times} \lrm{\pi} $ square box with stress-free boundary conditions. The flow is steadily forced by the addition of a source $\sin nx\sin ny$ to the vorticity equation; attention is restricted to even $n$ so that the forcing has zero integral. Numerical solutions with $n= 2$ and $6$ show that at high Reynolds numbers the solution is a domain-scale vortex condensate with a strong projection on the gravest mode, $\sin x\sin y$. The sign of the vortex condensate is selected by a symmetry-breaking instability. We show that the amplitude of the vortex condensate has a finite limit as $\nu \ensuremath{\rightarrow} 0$. Using a quasilinear approximation we make an analytic prediction of the amplitude of the condensate and show that the amplitude is determined by viscous selection of a particular solution from a family of solutions to the forced two-dimensional Euler equation. This theory indicates that the condensate amplitude will depend sensitively on the form of the dissipation, even in the undamped limit. This prediction is verified by considering the addition of a drag term to the Navier–Stokes equation and comparing the quasilinear theory with numerical solution.

Simulation on the Process of Cavity Wall Expansion of Cone at Constant Speed Water-Entry

2013 ◽  
Vol 419 ◽  
pp. 97-102
Author(s):  
Wei Cao ◽  
Chun Tao He ◽  
Cong Wang
Keyword(s):  
Computational Simulation ◽  
Water Entry ◽  
Constant Speed ◽  
Cavity Wall ◽  
Navier Stokes ◽  
Navier Stokes Equation ◽  
Half Angle ◽  
Expansion Dynamic ◽  
Different Depths ◽  
Volume Method

Computational simulation investigation which is based on the Navier-Stokes equation, finite-volume method, dynamic mesh method, and volume of fluid method, was carried out principally on the constant speed vertical water entry of the cone with 75 degree and a half angle. Based on this, the cavity generation and the process of cavity wall expansion of the cone with 75 degree and a half angle were analyzed. Through analyzing the expansion dynamic for the cavity wall in different depths, the velocity and acceleration with time in the process of cavity wall expansion were obtained, and the disturbances and splash feature laws of the free surface near the entrance of the cavity after cones water-entry were analyzed too.

Cavitation Bubble Collapse in Viscous, Compressible Liquids—Numerical Analysis

1965 ◽  
Vol 87 (4) ◽  
pp. 977-985 ◽  
Author(s):  
R. D. Ivany ◽  
F. G. Hammitt
Keyword(s):  
Surface Tension ◽  
High Pressures ◽  
Numerical Solutions ◽  
Compressible Liquid ◽  
Navier Stokes ◽  
Bubble Collapse ◽  
Navier Stokes Equation ◽  
Scaling Parameters ◽  
Collapse Behavior ◽  
Normalized Solution

Collapse of a spherical bubble in a compressible liquid, including the effects of surface tension, viscosity, and an adiabatic compression of gas within the bubble is investigated by numerical solutions of the hydrodynamic equations. A limiting value of shear viscosity causes the bubble collapse to slow down markedly, for both compressible and incompressible liquids, whereas moderate viscosities have very little effect on the rate of collapse. The inclusion of surface tension and viscosity introduces two scaling parameters into the solution, so that a single normalized solution is no longer sufficient to describe collapse behavior. The magnitude of the density changes calculated for the compressible liquid and the extremely rapid changes with time suggest that the usual Navier-Stokes equation of motion may not be appropriate. The possibility of liquid relaxational phenomenon and its contribution to sonoluminescence is considered. Shock waves or damagingly high pressures are not generated during collapse at a distance in the liquid equal to the initial radius from the center of collapse, although they will appear at such a distance if the bubble rebounds.

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