Forced convection Benchmark problem

Raj

I need to solve a simple benchmark problem in FLUENT related to forced convection with heat transfer. Can anybody suggest a simple problem with known results so that I can compare with the FLUENT results.

I tried to solve the Dittus-Boelter equation for fully developed flow in a pipe to find the heat transfer coefficient "h".But I could not get the correct results. As per theory, "h" will decrease and should reach a constant value in the fully developed region. But the FLUENT results shows a continous decrease in "h" all along the length whatever may be the pipe length.

Can anybody help me in solving my problem.

Regards Raj.