Heat Flux versus Wall Heat Flux: inlet - outlet energy, different values
 

Hi everyone,

I need to quantify the energy variation between the inlet and outlet of a compressor (SST, constant temperature on walls, Mach < 0.4).

After reading the CFX manual, it's not clear to me. When I run:


I get a very different result from:


Why is this happening, I don't understand.

The CFX manual says more or less that they are the same but Heat Flux is calculated by the CFD-POST while Wall Heat Flux solver.

The intuition tells me that Wall Heat Flux is incorrect because the result is very small while Heat Flux has an order of magnitude of the energy introduced by the rotor (mechanical energy transformation by rotation).

Please, does anyone know what I'm doing wrong, could it be that Wall Heat Flux can only apply on wall (boundary condition), not inlet?

Thank you very much for any contribution.

The inlet and outlet are not walls, so why do you want to calculate the wall heat flux for them?

I would suspect that wall heat flux is then just taking the small bit of wall heat flux in the inlet or outlet patch occurring at the control volume adjacent to the wall - which does not sound very meaningful.