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#1 |
New Member
Tim Anonym
Join Date: Sep 2015
Posts: 2
Rep Power: 0 ![]() |
Dear Foamers,
I struggle with this testcase for a while now. I've got an instability issue with a rhoSimpleFoam case. I'm using total pressure and total temperature at inlet and static pressure at outlet. Additionally the direction at inlet is given. I turned the turbulence off for simplicity. The case files are attached. The basic setup is as follows: Geometry: 2D, rectangle, 2 sides are connected cyclic, inlet, outlet originally there was a turbine blade in the middle, which i removed for simplicity Boundary conditions(p, T, U) inlet: totalpressure, totaltemperature, pressureDirectedInletVelocity outlet: fixedValue, zeroGradient, inletOutlet solver: rhoSimpleFoam If i run the solver, velocity rapidly increases at inlet and consequently (or the other way round) pressure drops. Then the flow at outlet reverses and the calculation diverges. I really need some advice, what causes the instability. Thanks for your help! Greetings, Tim |
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#2 |
Senior Member
Join Date: Oct 2015
Location: Germany
Posts: 100
Rep Power: 10 ![]() |
Is your issue solved yet? Just a guess: I had quite a similar problem which I solved by setting 'value' to 'uniform 0' (in 'p.totalPressure'). It seems like this offers the solver more "flexibility" to adjust dynamic and static pressure at the boundary - but I did not look very close at it.
Regards |
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#3 |
New Member
Tim Anonym
Join Date: Sep 2015
Posts: 2
Rep Power: 0 ![]() |
Thanks for your reply.
Setting the initial value of p at inlet to 0 gives an error, because I'm doing a compressible case. Setting it close to 0 doesn't seem to change the problem. I'm open for any further suggestions. Just give the ideas. Nothing can be worse than it's now. |
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#4 |
New Member
larmes
Join Date: Aug 2016
Posts: 26
Rep Power: 10 ![]() |
did you solve your issue?
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Tags |
divergence, rhosimplefoam, totalpressure, totaltemperature |
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