how to set boundary condition

jai

i'm really feel very hard to setting boundry condition, bcoz some times some set of boundary condition working and some time it won't work with other type of simulation.

for turbo machine type analysis, which type of boundary condition(for inlet and outlet) should be give & why?

for heat exchanger type of application[steam enter into the domain and leave the domain which is not parallel to the inlet passage and water domain is like a 'U' path], which one and why?

also suggest some materials to understand those things