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March 10, 2013, 22:19 |
nonNewtonianIcoFoam, wired nu
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#1 |
Senior Member
Dongyue Li
Join Date: Jun 2012
Location: Beijing, China
Posts: 838
Rep Power: 17 |
Hi FOAMERS,
I want to testify a simple case to try nonnowtonian fluid. transport dic is this: Code:
transportModel CrossPowerLaw; CrossPowerLawCoeffs { nu0 nu0 [ 0 2 -1 0 0 0 0 ] 5e-5; nuInf nuInf [ 0 2 -1 0 0 0 0 ] 5e-2; m m [ 0 0 1 0 0 0 0 ] 20; n n [ 0 0 0 0 0 0 0 ] 0.2; } But I got the result is like this: I think the nu in the bottom cornor should be big,but its not. Whats the problem? Thanks in advance. just run nonNewtonianIcoFoam This problem has been handled. nu0 and nuInf is contrary. Another issue: What is m? is it consistency index? But the dimension is s which is different with pa.s^n. Last edited by sharonyue; March 11, 2013 at 03:40. |
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March 12, 2013, 08:06 |
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#2 |
Senior Member
Dongyue Li
Join Date: Jun 2012
Location: Beijing, China
Posts: 838
Rep Power: 17 |
Does anyone know whats the mean of "m"?
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March 12, 2013, 10:06 |
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#3 |
New Member
Daniel Duque
Join Date: Jan 2011
Location: ETSIN, Madrid
Posts: 28
Rep Power: 15 |
I found this in file src/transportModels/incompressible/viscosityModels/CrossPowerLaw:
Code:
Foam::tmp<Foam::volScalarField> Foam::viscosityModels::CrossPowerLaw::calcNu() const { return (nu0_ - nuInf_)/(scalar(1) + pow(m_*strainRate(), n_)) + nuInf_; } |
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March 12, 2013, 10:11 |
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#4 | |
Senior Member
Dongyue Li
Join Date: Jun 2012
Location: Beijing, China
Posts: 838
Rep Power: 17 |
Quote:
Thanks all the same. in the Cross viscosity equation, it should be like this. and m is the consistency index which dimension is pa*s^n. Code:
Foam::tmp<Foam::volScalarField> Foam::viscosityModels::CrossPowerLaw::calcNu() const { return (nu0_ - nuInf_)/(scalar(1) + m_*pow(strainRate(), n_)) + nuInf_; } Last edited by sharonyue; March 12, 2013 at 22:02. |
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March 12, 2013, 22:16 |
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#5 |
Senior Member
Dongyue Li
Join Date: Jun 2012
Location: Beijing, China
Posts: 838
Rep Power: 17 |
Yesterday I just run a case.Actually I dont know what does m mean,But I set it like this:I think its like a kind of gum.
Code:
phase1 { transportModel HerschelBulkley; rho rho [ 1 -3 0 0 0 0 0 ] 1000; HerschelBulkleyCoeffs { nu0 nu0 [ 0 2 -1 0 0 0 0 ] 0.05; tau0 tau0 [ 0 2 -2 0 0 0 0 ] 0.01; k k [ 0 2 -1 0 0 0 0 ] 0.2; n n [ 0 0 0 0 0 0 0 ] 0.2; } } phase2 { transportModel Newtonian; nu nu [ 0 2 -1 0 0 0 0 ] 1.48e-05; rho rho [ 1 -3 0 0 0 0 0 ] 1; } sigma sigma [ 1 0 -2 0 0 0 0 ] 0.07; Result of alpha looks okay. in 5 sec, there are some bubbles trapped in the gum. But nu is not good especially in the final time. When its 5 sec, air is in the top and the gum is in the bottom. but nu is the same all the field.Whats going wrong? Thanks in advance. |
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