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Reply To: Natural convection simulation divergence issue

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Ali Fauze

Dear Dr. Mathias,

I appreciate your prompt response. After running the simulation with the Rayleigh-Bénard 3D example parameters, adjusting Ra and Pr values, I am pleased to report that the simulation did not diverge. However, the results obtained were unexpected. I observed the flow temperature and density both increased, contrary to the anticipated decrease in density. I attempted to fixe this issue by modifying the ThermalUnitConverter, and changing the physics model. Unfortunately, the simulation now diverges at the first time step.

Given that my ∆T is approximately 205°C, I am uncertain about the appropriate characteristics to assign to the ThermalUnitConverter at this temperature. Could you provide guidance on which temperature the characteristics shoud be assigned (Tmax or T0 …)?

Additionally, I would like to inquire if there is a recommended method for tracking convergence, like the transport equations used in RANS simulations.

Best regards,