[ghobold]

I'm having trouble understanding how gradients are obtained by CFD-Post. I am running an adimensional problem in Fluent and I want to calculate the Nusselt number in CFD-Post. However, whenever I probe the temperature gradient on the pipe wall, Fourier's law is never obeyed. In other words:

probe(Wall Heat Flux)@wallPoint ≃ 1 (which is what is set up in Fluent, so it's OK), but

-probe(Thermal Conductivity)@wallPoint*probe(Temperature.Gradient )@wallPoint ≃ 0.719, which contradicts Fourier's law.

It's an axisymmetric problem (simple circular duct), so Temperature.Gradient Y ≃ Temperature.Gradient, but Fourier's law is not obeyed.