Different boundary condition for different scalar fields
 

Hello,

I have two temperature fields, a solid temperature T_s and a fluid temperature T_f. These are created as two separate volScalarFields, modelling a flow though packed spheres between parallel plates, the upper wall is heated with a constant heat flux and the lower wall is adiabatic. I am just solving a scalar transport equation for both temperatures.

I set the temperature of the fluid T_f = 300K at the inlet. My reference says to set the solid temperature T_s = T_f at the upper wall of the parallel plates where the constant heat flux condition is located.

For the constant heat flux condition at the upper wall I need to set the gradient of the fluid temperature dT_f/dy = q/k. T_f at the wall is not known in advance and must be computed as part of the solution. Once it is known, I need to set T_s = T_f at the upper wall.

I have set fixedGradient at the upper wall, which works for the fluid temperature, but I wondered how use a separate boundary condition for the solid temperature at the upper wall?

Thanks in advance for any help,

A.