Screen Channel Liquid-Acquisition-Device Bubble Point Tests in Liquid Oxygen

This paper examines the key parameters that affect the bubble point pressure for screen channel liquid acquisition devices in cryogenic liquid oxygen at elevated pressures and temperatures typical of a high-pressure propellant tank. An in-depth analysis of the effect of varying liquid temperature, pressure, and pressurization gas type on the bubble point is presented. Testing of a 200 x 1400 and 325 x 2300 Dutch twill screen sample was conducted at the NASA John H. Glenn Research Center at Lewis Field in Cleveland, Ohio. Test conditions ranged from 92 to 130 K and 0.138 to 1.79 MPa. The bubble point is shown to be a strong function of temperature with a secondary dependence on the amount of liquid subcooling. The subcooling dependence is believed to be a function of the amount of evaporation and condensation occurring at the liquid-gas interface at the screen. Good agreement exists between the data and theory for normally saturated liquid, but the model generally underpredicts the bubble point in subcooled liquid. Using the liquid temperature at the screen as opposed to the bulk liquid temperature to determine the surface tension of the fluid results in better correlation with the data.