Steps to simulate plate heat exchanger
 

Hi!

I want some guidance in heat transfer analysis of plate heat exchanger. The domain consists of 5 bar pressurized fluid (water) enclosed by two plates only (for simplicity). I used both buoyantSimpleFoam and buoyantPimpleFoam solvers with inlet temperature specified but the solution crashes. The errors are related to negative initial temperature and courant number in order of 1e4 in pimple solver. I believe I'm giving wrong boundary conditions

Please guide me what boundary conditions should I use and how should I proceed with the problem.. should I make my domain multi region? I didn't use multiregion since Im going to analyze only one fluid in the start and not two. I am attaching my boundary conditions