Numerical Study of the Liquid Oxygen Draining in a Spinning Tank with Baffles for Hybrid-Propulsion Rocket

Abstract

Computational Fluid Dynamics (CFD) study of liquid oxygen draining in a spinning tank with and without baffles is carried out for hybrid propulsion rocket. The effect of tank spinning and the presence of baffles on the vortex formation and unusable propellant mass is brought out in this work. The interface of the draining propellant is captured using the Volume of Fluid (VOF) framework while the motion of baffles is simulated through mesh motion technique. Initially, analysis of liquid oxygen draining is carried out in a stationary tank without baffles. It is found that that a vortex is formed in the tank and gas entry in the feed line happens at 21s resulting in unusable propellant of 1.9kg. Subsequent analysis of liquid draining in a spinning tank without baffles shows that gas enters into the feed line earlier as compared to the stationary tank. Finally, the analysis is carried out for propellant draining in spinning tank with baffles. It is found that the momentum imparted by the baffles to the draining fluid increases the unusable propellant mass further compared to tank without baffle.