Heat Transfer
 

Helllo Folks!!!

I have a simple problem but i am not been able to track it properly.

Two fluids are mixing 1 hot at 250 C and the other cold at 180 C. (Multi-phase model)
I want to have heat transfer between the fluids.
Just switching on the energy equation is not favoring the heat transfer.
So i decided to use Renz-Marshal as the heat transfer mechanism in this . But the Nussult number calculated by Renz-Marshal law is not for such problems.
So anyone tell me how can i calculate the Heat transfer from fluid to fluid region.

Thanks Folks for reading it and much more thanks if you provide any small suggestion to me.

Regards
Shk