Simulation and optimization of stored gas pressurizing system for liquid propellant tanks in a launch vehicle

The primary purpose of this paper is to simulate the ldquostored gas type pressurizing systemrdquo for propellant tanks in a launch vehicle. Preventing the cavitation occurrence in propellant pumps (as the propulsion requirement) and providing required level of pressure in propellant vessels to prevent them from buckling against external aerodynamic forces (as the structural requirement) are the two most important goals of this system. In this paper primarily the basic equations have been derived. A quasi-steady iterative process has been selected to march in time domain. The simulation has been done with time marching steps to take into account the prediction of pressure change in propellant vessels´ ullage and propellant pumps´ inlet flow during the working time. An optimization has been done to obtain the best system properties such as cutting time and the minimum number of supplier capsules which should be carried by the launch vehicle.