||November 14, 2011 11:14
natural convection in stratifeid zone
The problem is: For different solver setting I'm experiencing natural convection in zone, where initialized temperature gradient is less than the lapse rate - convection should't occure.
I'm investigating convection in closed cube 3kmx3kmx2km with adiabatic boundary condition (hex grid 150000 elements). Initialized temperature gradient is decreasing 0,5K/100m (adiabatic lapse rate is 1K/100m). I've tried: boussinesq, ideal gas, and real gas for a density model, for both solvers: density, and pressure based (presto, second order for everything). I don't even know solver type matters, probably not. UDF is written fine. In every case convection occured. Somebody have any idea?