Determination of Liquid/Gas Interface and Liquid Center of Mass for GPM Tank with PMD Using Surface Evolver

摘要

Many spacecraft, such as the Global Precipitation Mission (GPM) spacecraft, use propellant management devices (PMDs) to control liquid propeUant within propellant tanks. Surface Evolver, an energy minimization routine, is used to find liquid-gas interface shapes and propellant center of mass locations, due to surface tension, for varying initial liquid positions, contact angles, and fill fractions for the GPM tank with a PMD. This study shows that Surface Evolver can accurately model the liquid-gas interface and liquid center of mass location for a complicated tank and PMD. The Surface Evolver results show that the initial position of the propellant, the contact angle between the propellant and solid surfaces, and the fill fraction of the propellant can drastically affect the liquid-gas interface in the tank and thus the center of mass of the propellant.