EFFECT OF SURFACE ENERGY ON THE LIQUID-VAPOR INTERFACE CONFIGURATION DURING WEIGHTLESSNESS

Abstract

As a part of the overall study of the behavior of rocket-engine propellants stored in space-vehicle tanks while exposed to weightlessness and solar and planetary' radiant heat sources, an analytical and experimental investigation was conducted to determine the effect of surface energy on the li~uid-vapor interface configuration during weightlessness.An experiment with a capillary tube geometry verified the contention that the solid-li~uid-vapor system tends to a configuration in which the free-surface energies are a minimum.This energy minimization process can significantly alter the li~uid-vapor interface configuration depending on the geometry employed.The effect of using a capillary tube as a surface~tensionbaffle in a spherical and a cylindrical tank on the zero-gravity e~uilibrium li~uid configuration was such that the li~uid was positioned in the lower portion of the tank with the vapor located at the top of the tank. ' '~,I ~,