FLOW-THROUGH-SCREEN PRESSURE DROP MODEL FOR SCREEN CHANNEL LIQUID ACQUISITION DEVICES

Recent comparison of storable and cryogenic propellant data indicates that liquid acquisition device screen properties may vary with temperature due to the thermal contraction of the screen when placed in a cryogenic liquid. This paper presents theoretical analysis and steady-state finite element analysis simulations to determine the extent that each screen property is temperature dependent. New, more accurate equations are developed to calculate the screen properties used in the flow-through-screen (FTS) pressure drop model. Results show that the screen properties do not vary significantly with temperature, with a maximum difference of 0.3% at liquid hydrogen temperatures. This indicates that the current FTS pressure drop model is valid and does not require temperature-dependent screen properties, and that the differences between simplified bubble point (BP) model and cryogenic BP data is strictly due to changes in surface tension due to evaporation and condensation at the liquid-vapor interface.