|April 5, 2013, 15:37||
Natural Convection: Energy residual does not converge
Join Date: Apr 2013
Posts: 1Rep Power: 0
I am relatively new to CFD.
I am simulating natural circulation in a small box (~6inx6inx16in tall box) with 2 heater rods placed inside along the height and gravity. The rods have 'heat source' thermal conditions; one rods is at 400W, the other at 250W. The top wall of the box has a heat source condition as well of -650W. The fluid in question is water (using a polynomial in T density because the IAFW water thing generally gave me errors with T and P out of bounds).
I have run the simulation with various physics continua and solver settings and finally have a solution that appears realistic. I have also refined mesh and I don't think that is an issue. The problem is that under all of the continua and solver settings I have tried (whether turbulent/laminar or steady/unsteady) my energy residual flattens out at just over 10. The XYZ momentum residuals are 10^-5, continuity 10^-3. Under turbulent models (K-Omega) TKE is about 10 and SDR is about 0.01.
My question may simply be answered by telling me that a high energy residual in a natural convection simulation in STAR CCM is normal and acceptable. Otherwise I would appreciate some opinions; I can list more simulation parameters.
|April 10, 2013, 08:53||
siamak rahimi ardkapan
Join Date: Jul 2010
Location: Copenhagen, Denmark
Posts: 218Rep Power: 9
I do not think that it is normal. I think there is a problem. Are you sure that the solution is converged? check if the solution is converged
|Thread||Thread Starter||Forum||Replies||Last Post|
|pimpleFoam: turbulence->correct(); is not executed when using residualControl||hfs||OpenFOAM Running, Solving & CFD||3||October 29, 2013 09:35|
|calculation stops after few time steps||sivakumar||OpenFOAM Running, Solving & CFD||7||March 17, 2013 07:37|
|High Courant Number @ icoFoam||Artex85||OpenFOAM Running, Solving & CFD||9||January 3, 2012 09:06|
|Orifice Plate with a fully developed flow - Problems with convergence||jonmec||OpenFOAM Running, Solving & CFD||3||July 28, 2011 05:24|
|Extrusion with OpenFoam problem No. Iterations 0||Lord Kelvin||OpenFOAM||6||April 12, 2011 11:24|