Thermal analysis of a cryogenic liquid acquisition device under autogenous and non-condensable pressurization schemes

This paper presents thermal analysis of a 325 × 2300 mesh LAD sample that was tested over a wide range of liquid methane temperatures (106-160 K) and pressures (0.0618-1.78 MPa) for a LAD using both autogenous (gaseous methane) and noncondensible (gaseous helium or nitrogen) pressurization schemes. To compare between schemes, screen interfacial temperatures, screen Reynolds numbers, condensation and/or evaporation mass flow rates at breakdown, and heat fluxes produced at the screen are computed as a function of liquid temperature and pressure. Condensation and evaporation rates are also computed using kinetic theory to allow comparison. Each parameter has a profound impact on surface tension and thus the performance of the LAD screen. The understanding gained here will be used to determine optimal propellant pressure and temperature operating regimes and will help mission designers determine whether autogenous pressurization is feasible for future space missions.