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interPhaseChangeFoam: sqrt(negativeValue) in SchnerrSauer |
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November 16, 2010, 10:03 |
interPhaseChangeFoam: sqrt(negativeValue) in SchnerrSauer
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#1 |
Member
David Hora
Join Date: Mar 2009
Location: Zürich, Switzerland
Posts: 63
Rep Power: 17 |
Hi everybody
A negative saturation pressure can cause a floating point exception in the following function: Foam:haseChangeTwoPhaseMixtures::SchnerrSauer: Coeff ( const volScalarField& p ) const { volScalarField limitedAlpha1 = min(max(alpha1_, scalar(0)), scalar(1)); volScalarField rho = (limitedAlpha1*rho1() + (scalar(1) - limitedAlpha1)*rho2()); return (3*rho1()*rho2())*sqrt(2/(3*rho1())) *rRb(limitedAlpha1)/(rho*sqrt(mag(p - pSat()) + 0.01*pSat())); } The problem occured in 'sqrt(mag(p - pSat()) + 0.01*pSat())' when I tried to reduce the saturation pressure stepwise from an initial solution without cavitation. I know that a simple solution would be to use a higher pressure level but that's not really satisfying in my opininion. Does anybody know more about the term 0.01*pSat? I found some papers (not the referenced one) but this term is never mentioned. Regards David |
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November 17, 2010, 03:51 |
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#2 |
Member
David Hora
Join Date: Mar 2009
Location: Zürich, Switzerland
Posts: 63
Rep Power: 17 |
I use
return (3*rho1()*rho2())*sqrt(2/(3*rho1())) *rRb(limitedAlpha1)/(rho*sqrt(max(mag(p - pSat()),dimensionedScalar("p",dimensionSet(1,-1,-2,0,0,0,0),VSMALL)))); as intermediate solution. Any comment is very appreciated. Regards David |
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February 20, 2014, 07:57 |
hi
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#3 | |
Senior Member
Baris (Heewa)
Join Date: Jan 2013
Location: Japan
Posts: 130
Rep Power: 13 |
Quote:
Maybe it is a bit late but for few months i started to interested indeed with openfoam and try to make cavitation simulation in nozzle by using interphasechangeFoam. I have faced same problem too. Could you tell me that what is the meaning of mag(p - pSat()) + 0.01*pSat()) ??? i hope that you already got answer about it and your help will be very appreciated. Best Regards... |
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