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January 3, 2013, 11:04 |
setting BC for T field
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#1 | |
Member
Jamal
Join Date: May 2012
Location: Freiburg
Posts: 54
Rep Power: 13 |
Dear
I am working on a 2D wedge germetry having an inlet at the top and an outlet at the bottom of the wedge. U and T file are given below..... Quote:
I am using a solver which is a combination of buoyantPimpleFoam and buoyantBousi..PimpleFoam and I hope its working well. I think I need to review boundary conditions of T and U, but ?? Please let me know how I can fix this problem... |
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January 4, 2013, 06:29 |
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#2 |
Senior Member
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Can you please, elaborate your problem?
As, it appears to me that a heated fluid enters the wedge, but I am bit confuse with the flow direction. inlet { type fixedValue; value uniform (0 -1 0); } where excatly the fluid is flowing?? |
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January 4, 2013, 08:58 |
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#3 |
Senior Member
Bernhard
Join Date: Sep 2009
Location: Delft
Posts: 790
Rep Power: 22 |
Can you maybe show a piece of your log file? Is the solution converged?
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January 4, 2013, 12:18 |
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#4 |
Member
Jamal
Join Date: May 2012
Location: Freiburg
Posts: 54
Rep Power: 13 |
Dear
Fluid is entering the wedge vertically downward through an inlet patch which is located at left top corner and leaving the wedge vertically from an outlet patch located at left bottom corner. Initial condition for inlet patch for U is (0 -1.0 0) and T is 823.15K and internal field value is 573.15K. As the simulation runs internal temperature increases which is obvious. And as simulation runs further the temperature at outlet patch increases (more than 900K) beyond the initially defined inlet temperature which is 823.15K. Which I think is not correct. Thanks |
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January 8, 2013, 03:55 |
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#6 | ||
Member
Jamal
Join Date: May 2012
Location: Freiburg
Posts: 54
Rep Power: 13 |
Dear
Here is a piece of log file ... Quote:
. . . Quote:
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January 8, 2013, 04:04 |
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#7 |
Member
Jamal
Join Date: May 2012
Location: Freiburg
Posts: 54
Rep Power: 13 |
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January 8, 2013, 10:22 |
combined solvers?
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#8 |
Senior Member
Fabian Roesler
Join Date: Mar 2009
Location: Germany
Posts: 213
Rep Power: 18 |
Hi,
so you combined buoyantBoussinesPimpleFoam with buoyantPimpleFoam for what purpose? Could this cause your problems? Some wrong defined conservation equation? Regards Fabian |
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January 24, 2013, 14:39 |
alphaEff
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#9 |
Member
Jamal
Join Date: May 2012
Location: Freiburg
Posts: 54
Rep Power: 13 |
Dear
You are right, I have combined the buoyantBoussinesqPimpleFoam with buoyantPimpleFoam in order to simulate an incompressible flow with temperature dependent density field. I have included pEqn, UEqn and hEqn in this solver. Right now every thing seems to be allright as I can run the simulation using the kEpsilon model and T and rho fields looks good to me. But the value of turbulent thermal diffusion (alphat) is too big. Would you tell me that how the alphaEff is calculated in the following equation of hEqn file ( fvm::ddt(rho, h) + fvm::div(phi, h) - fvm::laplacian(turbulence->alphaEff(), h) == - (fvc::ddt(rho, K) + fvc::div(phi, K)) ); as alphaEff=alphat+alpha according to doxygen and alphat is calculated by kEpsilon as alphat_ = mut_/Prt. What about alpha and why the value of alphat (turbulent thermal diffusion) is out of range. I am using the Prt value 7.0 in fluid RASproperties. I have attached a temp profile and rho profile and alphat just to show the simulation results. Please let me know what I have to consider to solve this problem Regards Jamal Last edited by aujamal20; January 24, 2013 at 14:42. Reason: pics are not uploaded |
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February 20, 2013, 14:59 |
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#10 |
Member
Jamal
Join Date: May 2012
Location: Freiburg
Posts: 54
Rep Power: 13 |
Dear OFrs
I am working on heat transfer multiregion case containg one fluid and two different solid regions. The solid regions have different thermodynamic properties as one of them is steel and other one is insulation region. So I need to have thermophysicalProperties file in constant folder but the problem is that I am unable to understand char and pmma key words. Can somebody explain what these things are and how their values can influence the simulation... Thanks in anticipation... |
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February 20, 2013, 16:25 |
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#11 | |
Senior Member
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Quote:
I met dame problem before with the same solver.but no one answered me. afer some search i found that these values may be the contribution of two different species in the solid region. Please share any other answer if you meet any answer in you way. Good luck |
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