Dynamical Model of Rocket Propellant Loading with Liquid Hydrogen

A dynamical model describing the multistage process of rocket propellant loading has been developed. It accounts for both the nominal and faulty regimes of cryogenic fuel loading when liquid hydrogen is moved from a storage tank to an external tank via a transfer line. By employing basic conservation laws, the reduced lumped-parameter model takes into consideration the major multiphase mass and energy exchange processes involved, such as highly nonequilibrium condensation evaporation of hydrogen, pressurization of the tanks, and liquid hydrogen and hydrogen vapor flows in the presence of pressurizing helium gas. A self-consistent theory of dynamical condensation evaporation has been developed that incorporates heat flow by both conduction and convection through the liquid/vapor interface inside the tanks. A simulation has been developed in MATLAB for a generic refueling system that involves the solution of a system of ordinary integro-differential equations. The results of these simulations are in good agreement with space shuttle refueling data.