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Boundary conditions low Mach number flow

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Old   November 28, 2010, 04:44
Default Boundary conditions low Mach number flow
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I'm trying to study a low Mach number flow with variable density using the SIMPLER algorithm. The real problem is that of a spherically expanding flame from a point source in an unconfined space.

The physical boundary conditions are the velocity u=0 at the origin and u=0 at the far-field and pressure p=p0 at the far-field. The problem is essentially 1-D so I use a 1-D domain with a staggered grid for computations.

It is my understanding that for such a problem I only have to define either pressure or velocity at the boundaries. I seem to be getting incorrect results and I think I have issues with boundary conditions. Right now I have,

at the centre, r=0, u=0

at the far-field, r=R, du/dr = 0

I use the discretised pressure equation to obtain the pressures at the boundary using the velocities calculated at the boundary, i.e. I don't specify a particular pressure value at the boundary, it is taken from the solution.

Can anyone tell me if I'm doing anything wrong? Thanks.
lost.identity is offline   Reply With Quote


bcs, simpler algorithm

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