Hello, I am using a Finite difference method for solving Incompressible N-S equations on a staggered grid in a driven cavity flow (SIMPLE with pressure correction method with Mat Lab). Does anyone have an idea about the boundary condition for pressure and velocity? I have velocity grid outside of domain and I was trying to implemented velocity as v(1,= -v(2, (or u) for points outside a domain (there is a wall between thus points with non slip condition), pressure on the boundary was the same as a pressure in a next point in, p(1,=p(2, (with dp/dx|_w = 0 and dp/dy|_w = 0 for y-direction). But I have not a god result. My program work well for channel flow (couetteflow). Can anyone help me with boundary condition?

You better fix the pressure at the center of the cavity along with the BCs you are using at present. I wonder, how did you get good answer for channel flow? Will you pl. tell me the details.

GS

hi i agree with Mr.singh.If that does'nt work try fixing the pressure some where on the lid( > than the initial assumption for pressure) by

what about the boundary condition for the moving lid?

some people put the boundary condition like this

u(i,j_max +1) = 2.0*(moving lid velocity) - u(i,j_max)

for i=1, ... , i_max.

This is from the book "Numerical Simulaton in Fluid Dynamics"

by Michael Griebel

Hello Dado,

In non-slip BCs velocities on the wall = 0 (u=0, v=0) except at 1 side (top). For pressure correction step you have a Neumann BC on the wall ( dp/dn=0 ). A pressure datum p=0 is specified at the middle of the bottom wall.

I'll tell u that singularities will develop where the boundary contour isn't smooth.

Enggar

Sir, i m doing my project on pressure correction techniques followed by Suhas Patankar. I m working on Simple, Simpler & Simplec algorithm applied on the problem "LID DRIVEN CAVITY". I need the codes in C or FORTRAN language. If u can give, it will oblige me.

sincerely urs Pavan Sharma Final Year, IIT Guwahati

[francisco.angel]

I know a long time has passed from when the question was asked, but here is a link for a cavity flow implementation in matlab:
http://www.mathworks.com/matlabcentr...en-cavity-flow
I haven't tested it myself though.
btw I'm developing a cavity simulation in Matlab, but I haven't finished yet.