Experimental study on the direct contact condensation of gaseous oxygen jets in crossflow of liquid oxygen

•First cryogenic experiments on the direct contact condensation of jets in crossflow.•Development of image processing methods for unstable flow patterns.•The plume length may decrease with increasing gas flow under cryogenic conditions.•Useful results on plume length, heat transfer coefficient and oscillation frequency. To ensure the safe and stable operation of the oxidant supply system in liquid oxygen (LOX)/kerosene liquid rocket engines, cryogenic visualization experiments on the direct contact condensation of gaseous jets in liquid crossflow are conducted using oxygen as the working fluid. The mass flux of gaseous oxygen (GOX) is 200–800 kg/m2s, while the temperature of LOX is 101 K. Under these operating conditions, violent oscillations occur. To address this problem, this paper proposes an image processing program to facilitate the study of flow patterns, oscillation frequency, plume length, and heat transfer coefficients in unstable flow fields. Three flow patterns are identified, namely condensation oscillation, chugging, and crawling. The effect of the GOX mass flow rate on chugging is investigated. In addition, the flow pattern map with the coordinates of nondimensional GOX mass flux and condensation driving potential is developed. The oscillation frequency, ranging from 120 Hz to 150 Hz, increases monotonically with the GOX mass flow rate and LOX pressure in the test section. The plume shrinks with the increase of the GOX mass flow rate, which differs from the experimental results reported for room-temperature working fluids. The dimensionless plume length varies between 4 and 6 and is fitted by a correlation relationship with discrepancies of ±5%. The heat transfer coefficient ranges from 0.1 MW/m2K to 0.5 MW/m2K and is also fitted by a correlation relationship with discrepancies of ±15%.