I have a pressurized tank with a total volume of 100L filled with nitrogen gas. The tank has an orifice of 20mm which vents out to atmosphere. The initial pressure in the tank = 100Mpa, and final pressure = 1Mpa. Initial temperature is 300K. I need to find the final temperature of the gas and also the time it would take for the gas to discharge causing the pressure change. Any guidance in solving this problem would be appreciated.