Can any tell me please what is the boundary condition in ansys icepak.
 

I'm doing thermal analysis of heat sink with three module .in the cabinet two side opening one side is min value & other side is max value. minimum side i'm giving 10m/s velocity. Three module wattage respectively 150w,90w,60w.
Heat transfer coefficient is 10w/k.m.I'm new to analysis filed .what if ask boundary condition means what should i say.

Please answer me clearly.

ANSYS Icepak does not have a forum for it - the fluent one may be more appropriate but I suspect not very useful.

But an overall comment: What heat transfer coefficient are you talking about? On the surface of the heat sink, or of the whole heat sink assembly?

ansys icepak boundary condition
 

For whole assembly. and also please explain to me what is convergence criteria.and difference between steady state thermal analysis & transient analysi.

This is basic CFD modelling stuff - you need to do the tutorial examples and read the documentation to understand the basics. I am not going to rewrite a textbook in a forum post to explain basic concepts like that (sorry).

Hello,
When I was simulating a propeller in CFX, I used both steady and transient method, however the lift in transient is 10% higher than in steady method. I don't know why that great differences happened. Can anyone help explain that. The physical timescale in steady method is T*1/180。the time step in transient calculation is also T*1/180.

Inaccurate simulation results can be caused by many things. Have a look in the FAQ page for the Ansys wiki on fd-online.