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-   -   [Broken-dam prob. (SIMPLE, VOF)] (http://www.cfd-online.com/Forums/main/3497-broken-dam-prob-simple-vof.html)

 Park May 21, 2001 04:27

[Broken-dam prob. (SIMPLE, VOF)]

Hi. I have two questions about broken-dam problem. I use SIMPLE method with VOF.

i) in inner iteration, can I solve algebraic eq. with SIP solver ? (need any other better solver ?)

ii) How can I give proper initial condition ? (especially in pressure)

Thanks.

 Onno May 22, 2001 03:38

Re: [Broken-dam prob. (SIMPLE, VOF)]

Regarding initial Pressures

If your code is implemented correctly, you may initialise the pressures with zeros.

As you are solving for unsteady flow you have to iterate each time step (inner loops) over the Simple loop till convergence. For the broken dam problem the initial velocities are zero. Thus the first momentum prediction consists of the gravity source term as the pressure gradients are zero. The first Simple calculation will now produce the Pressure field that is consistent with the gravity sources of the momentum prediction.

 Barney May 22, 2001 18:17

Re: [Broken-dam prob. (SIMPLE, VOF)]

1) I find the SIP solver solves these types of problems

but takes a few iterations to do so...

2) The Simple scheme takes in an initial guessed

and uses the pressure correction equation to

correct it... giving a better initial condition

will only improve your convergence...maybe you

mean boundary conditions???

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