NUMERICAL INVESTIGATION OF INTERFACE STABILITY IN REDUCED GRAVITY FOR THE APPLICATION OF ON-ORBIT REFUELING OF SPACECRAFT TANKS

Abstract

Launching a spacecraft with an adequate amount of propellant for long-range long-term missions is challenging. Therefore, it is imperative to have a mechanism to fill the propellant tanks in reduced gravity. Vented and no-vent filling are the two methods to fill tanks in reduced gravity. The interface stability during the vented filling of a tank under reduced gravity was investigated by carrying out 2D numerical simulations. Filling a tank partly filled with test liquid and also filling an initially empty tank were simulated for different volumetric inflow rates. Regimes of subcritical, critical, and supercritical flow were observed during the filling process. The critical inlet Weber numbers were determined. Furthermore, the reorientation of the liquid interface in reduced gravity was simulated and the final equilibrium position of the center point was found to be in good agreement with the predicted value. This paper is published with the permission of the authors granted to 3AF - Association Aeronautique et Astronautique de France (www.3AF.fr) organizer of the Space Propulsion International Conference.