[chinna]

hai, im simulating heat exchanger. i create interfaces and coupled them both to enable heat transfer.

for the solution part, i tried run with simple, simplec. i dont satisfied with the results.
so, can i use coupled solution method?? and as i go through user guide, it says coupled method gud for large time step size.. what does it means by large time step size?? can i go for 5s or 10s in one time step??

as usual,i wanted to find the temperature out of both fluid.
so can i use the above method??
and how should i fix the time step size and number of time step..??