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September 26, 2012, 12:01 |
units after multipl. with phi
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#1 |
Super Moderator
Tobias Holzmann
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Hi all,
I have an equation like that: Code:
div(phi, H) + Q I had a look at the phi file and the file has the unit [kg/s]. Also I had a look at the createCompressiblePhi.H file and there is phi defined as the mass flow. So after div(phi, H) I should get the unit [J/s] = [W] ... Or am I wrong? If phi = rho then everything would be nice I am a bit confused. Tobi |
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September 26, 2012, 14:07 |
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#2 |
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Meindert de Groot
Join Date: Jun 2012
Location: Netherlands
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Could it be that you are missing the cell volume from the finite volume integration in your Q term?
phi = rho would still not solve your problem, because you're still missing [1/s] in that case. |
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September 26, 2012, 14:12 |
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#3 |
Super Moderator
Tobias Holzmann
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Hi,
no its implemented in the flamelet tool from alberto. He added an enthalpy defect like that: Code:
div(phi, H) - laplacian(turbulence->mut/sigmat, H) + Qrad Code:
Qrad = 4 * sigma_B * (T_cell^4 - T_env^4) * as Qrad [W/m³] H [J/kg] Well - but you `re right. There is still a s missing :/ I a m confused with taht code. |
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September 28, 2012, 06:52 |
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#4 |
Member
Meindert de Groot
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Hi Tobi,
Have a look at equation 2.29 in the Programmer's Guide. |
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October 1, 2012, 11:30 |
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#6 |
Senior Member
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Hi Tobias,
the folks at OpenCFD have discontinued Programmers Guide that is correct but you can still find http://openfoam-extend.git.sourcefor...de.pdf;hb=HEAD |
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October 1, 2012, 14:32 |
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#7 |
Super Moderator
Tobias Holzmann
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HI,
thanks very much. Thats that what I need integration over a volume V - now I know how that works. Thought that the programmers-guide is only the doxygen-code Nice to know. Tobi |
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October 3, 2012, 18:24 |
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#8 |
Member
Meindert de Groot
Join Date: Jun 2012
Location: Netherlands
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Perhaps it's good to know that you can also find it in your $WM_PROJECT_DIR/doc/Guides-a4 directory.
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