Learning Forum

[l_srf]

Hi all,

I am new to Ansys. I need to apply a temperature-dependent heat flux (W/m2) into a surface as a boundary condition in an Ansys Mechanical transient simulation. 

The expression is: 
Heat Flux = (0.1*(Temp_surface - Tambient) + 1.5)/(20000/(0.01*(Temp_surface) + 2.5))
Where "Temp_surface" is the temperature of the surface I want to apply heat to. Note it will change with time as heat transfer occurs. Tambient is constant.

But I cannot enter it under Heat Flux -> Function, as it says the "temperature" is undefined. I can't find how or if it is possible to apply a heat-dependant expression for heat flux or even how to define the "Temp_surface" as a parameter.

Any thoughts? 

Many thanks

[dlooman]

Your equation may be closely approximated by a temperature dependent film coefficient.  To account for the change in the formula over time you can run the analysis in a number of steps and respecify the temperature dependent convection coefficint at the end of each step.