manu prabha anand

Air density do not know for comprssed gas at 8 bar we can calculate but uncertain over the flow in this condition, which in real application it must be varying, because it is cooled, but similar problem with  a pipe plow also i had posted it earlier that case it is impressile flow, it has constant air density. This also same with a simple pipe flow iposted earlier, that also in compressible flow we can consider contant density of 1.22kg/m3, but that also same results , error in pressure calculation? why? This preoblem also solved with pressure and mass flow outlet condition.