shell and tube heat exchanger...
 

Hii everyone,
I am working on shell and tube heat exchanger problem..in this problem I took two inlets( one for shell and other for tube) and two outlets.. I am taking water for shell inlet and ethylene glycol.. For tube inlet..How to solve this problem in CFX...is it important to create interfaces or not...and how to define materials in CFX...

Have a look at the tutorials provided with CFX. That will show you the basics.

I have started giving boundary conditions to heat exchanger...for example if I define water as shell inlet and ethylene glycol for tube inlet..there is a problem in fluid and particle definitions it automatically changes to water for both inlets...where does this problem occurs..please help me out...

CFX cannot use, by default, different fluids in different domains. This makes it a mutiphase simulation. You can get around this by disabling the ensure constant domain physics option. Have a search of the forum for information about this.