Requesting more information about heat transfer coefficient theory

Rahul_P1

Hello,

I am using AcuSolve to find heat transfer convection coefficients for some solid bodies rotating in a volume of fluid. I understand that this value is called 'surface_film_coefficient' in the solution outputs.

I am wanting to know the theory / equation that AcuSolve uses to calculate this value. Unlike some other solvers I haven't been able to find a Theory manual for AcuSolve which is the level of description I am interested in.

Thanks,

Andrew

Rahul_P1

Hi Andrew,

AcuSolve evaluates the surface film coefficient (convective heat transfer coefficient) from the turbulent near wall boundary layer similarly solution. This self similarity solution is valid for both velocity and temperature fields. AcuSolve uses the velocity one to impose turbulence wall conditions for the momentum equations. AcuSolve uses the temperature one to impose conditions for the energy equation. AcuSolve can also use the temperature self similarity solution to estimate the heat transfer coefficient. The beauty of this method is that AcuSolve does not even need to solve for the temperature field to get the film coefficient. Solver simply needs the flow equation solved and the thermal material properties, conductivity and Prandtl number to be given. Moreover, this solution
is rather accurate and non-oscillatory. It works for complex industrial problems where the flow may come from many different directions and with different temperature conditions. But it does requires knowledge of the edge location of the boundary layer (in terms of y+). Since this is extremely difficult to compute accurately for general industrial flows, AcuSolve estimates it as a large y+; which can be changed by the end user. The solution is very insensitive to this value.

Regards,