Learning Forum

[sjyang]

What is the difference between calculating the total heat transfer rate in the Fluxes section and calculating the total surface heat flux in the Wall Fluxes section of Surface Integrals in ANSYS Fluent?

 

 

When calculating the total heat transfer rate on a mass-flow-inlet surface in the Fluxes section, a non-zero value is returned. However, when calculating the total surface heat flux in the Surface Integrals section, it returns zero. I am curious to know why these results differ.

[Rob]

How do the two values compare on a wall?

[sjyang]

Hi, thank you for your response.

For a wall boundary condition(isothermal temperature wall condition), the surface integral of the total surface heat flux and the total heat transfer rate in the flux report yield the same value. 

However, as I mentioned, for a mass-flow-inlet(isothermal temperaure fluid condition), these two values are different. It is weird that the two values differ for the mass-flow-inlet. Could it be that only conduction heat transfer is considered in the surface integral of the total surface heat flux?

[Rob]

So you're wondering why a wall function doesn't agree with a flux definition on an inlet?