Wall heat transfer coefficient (HTC) problem
 

Dear fellows

I have a strange problem with HTC in CFX, I am simulating a simple problem of flow inside duct (isothermal wall), I had defined the tbulk for the expert parameter in the ansys solver, and the results were very good for velocity and temperature profiles except for wall heat transfer coefficient and also wall heat flux, its profile is very good i.e. maximum at entrance then decreases until maintained constant as the profile said but the range of this profile from ZERO to reasonable value, my question is how the wall HTC and heat flux reaches zero and in fact, it did not maintains constant, it varies along the duct from the entrance to exit.


best regards

That obviously depends on what the flow is doing. You have not described your flow at all.