Boundary Condition For Pressure vessel Problem
 

Hi All,

I am solving a Unsteady CHT problem of pressure vessel 1 m dia and 10 m lenght, containing gas at 200+ bar. Vessel is covered with solid material 0.25 mm thickness. Gas is released suddenly from a opening, which causes sudden drop in Temp. from 300 k to -146 k. Mass flow rate @ outlet is 16 kg/s.
Now which BC should I give mass flow outlet or pressure outlet(@ 0 gauge pressure) or any other BC? Also is it necessary to specify heat transfer coeff. at outer solid surface, as am not simulating the outer domain?


Thanks in advance.