Forced convective heat transfere with fixed heat flux?
 

Hallo,

first, what do I want to do.

I want to simulate the heating of water in a pipe whichs walls are heated.
The heat flux,which i know, across the wall is supposed to be konstant.

I want to use k,Omega turbulence model in steady state.

I know the water temperature, viskostity, k, omega at the inlet.
I know the surfaice roughness at the wall. So I can use a wall funktion for k and omega. (The turbulent part of the system)

What I don't know and do not want to gues is the heat transfere coefficient, because that is exactly what I am looking fore.

The solvier is buoyantSimpleFoam.

If I try to use turbulent heat flux temperature at the wall the wall temperature is much much much too hich.

If I use konstant wall temperature the amount of heat transfered into the water seems to be reasonably correct.

There is an unresolved thread regarding the same problem in the forum.

I think that it is common to have a fixed heat flux and calculate the heat transfered to a fluid so it should not be too difficult to do that.

I would be very thankfull for information clarifiying what I am doing wron in using fixed heat flux.

Thanks a lot.

Best regards.

Benjamin