[andred]

The model is that:Cold water in a twisted tube was heated by the wall of the tube and the temperature of the wall was set as a constant ,I want to get the distribution of the surface heat transfer coefficient along the axial direction of the tube

I know that we can get the heat flux and the surface heat transfer coefficient via wall-flux--surface heat transfer coefficient, The result is computed from a reference temprerature,and it is a constant value when I compute it along he whole tube ,But acturally the reference temperature should be the average teperature of the tube cross section which is not a sonstant,So how can I get the distribution .

what's more, Someone tell me that their is a macro "Bounday_heat_flux(f,t)" But I don't konown how to use it!