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buoyantBoussinesqSimpleFoam
3 Attachment(s)
Hi,
using the buoyantBoussinesqSimpleFoam (in Open Foam 2.1.1) I am trying to solve the laminar Rayleigh-Benard convection (laminar natural convection in a square cavity heated from bellow) for Pr=10 and Ra=1e05. I have set up the case, run the solver... Unfortunately, results for the dimensionless temperature and horizontal velocity along the vertical mid-plane (i.e. along x/L=0.50) are "not good"! They are compared with the results of O. Turan, N. Chakraborty, R.J. Poole (2012). Laminar Rayleigh-Benard convection of yield stress fluids in a square enclosure, Journal of Non-Newtonian Fluid Mechanics, Vol. 171-172, p. 83-96 and with the results obtained with "commercial" code! Can someone please check if I have done any obvious mistakes in setting up the case or is the problem with the solver?? In addition, I have the following question. Why is it necessary to have the following files (required for a turbulent flow) in a 0 directory - alphat, epsilon, k, kappat, nut??? If I run the case without these files (in a 0 directory) I get the following message: --> FOAM FATAL IO ERROR: cannot find file file: /home/ternik/OpenFOAM/ternik-2.1.1/Cavity_RayleighBenard/0/kappat at line 0. From function regIOobject::readStream() in file db/regIOobject/regIOobjectRead.C at line 73. FOAM exiting Cheers, Primoz |
They have a non-Newtonian fluid - you don't.
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is there anybody willing to help (assist) to correctly set up and solve this "test case"!? i think we will all benefit from this... Enjoy, Primoz |
1 Attachment(s)
Dear Primoz,
can you evaluate the attached modified case? I think convergence is much better and at a first glance results look fine... I think the most important change is the relaxation factor for p_rgh. Martin |
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thanks a lot for your tip(s). i have run your case and although that the convergence is much better the results are still not O.K.! As a matter of fact they are similar to the one I have presented in my original post. Since te velocity field is almost zero, I have started to question the boundary conditions for the pressure (especially for p_rgh). What do you think? If you will find time, please check this link https://unihub.ru/tools/ofservice/br.../buoyantCavity and associated b.c. for the pressure. All the best, Primoz |
Dear Primoz,
I am facing the same problem. Did you find appropriate BC for p_rgh? |
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