[MohammadB]

Hi everyone
I've got three serious problems in simulating turbulent flow of water(Re=95922) in a spiral pipe installed on a water circulating panel exposed to radiation on one side.
1_ the rate of heat transfer to water is highly impprtant to me, what would be 2 of the best turbulence models for this problem? What are the required y+ and meshing settings?
2- what methods do you advise?
3- As you can see in attached photos the residuals especially continuity residuals don't get converged. Do I have to continue until continuity residual is below 1e-6 or if it say reaches 1e-3 or 1e-4 and stays consistent is sufficient? How do I reduce the residuals?
I would appreciate it greatly if someone who knows the answers would help me...