Experimental study on liquid oxygen chilldown in the horizontal pipe with an injector on the exit

Components downstream of the pump in the cryogenic liquid rocket engine were simplified to a horizontal pipe upstream of an injector. Cryogenic chilldown was investigated experimentally in this pipe by constant flow rate of LO2. The chilldown processes were discussed and the boiling curves were drawn to identify the boiling transition points, Leidenfrost point (LFP) and critical heat flux point (CHF). By fitting the present sets of data, correlation formats of the previous expressions were selected and revised linearly to give the suggested correlation expressions on T-Leid, q(Leid), T-CHF and q(CHF). Because these parameters could also be well correlated to the corresponding pressure, it could be supposed that the effects of pressure could be well represented by the physical properties of the fluid. The recommended correlations on T-Leid, q(Leid), T-CHF , include the physical properties of fluid only. The recommended correlation on q(CHF), include both the sensor position (L-se) and the physical properties of fluid. Furthermore, a couple of previous correlations based on cryogenic chilldown were validated, at least partially.