Abstract
This paper presents new cryogenic two-phase heat transfer coefficient data for the chilldown of large diameter, long propellant transfer lines using liquid oxygen (LOX) and liquid methane (LCH4). At the NASA Neil A. Armstrong Test Facility, as part of the Integrated Cryogenic Propulsion Test Article test campaign which included the first ever cryogenic-lander engine hotfire testing at thermal vacuum conditions, liquid oxygen (LOX) and liquid methane (LCH4) flow boiling data was gathered during propellant feedline conditioning. Ten horizontal chilldown tests were conducted on a 2.54 cm and 11.43 cm transfer line in two different thermal environments, using two cryogens, over the range of inlet pressure (100–450 kPa), mass flux (100–6000 kg/m2*s), Reynolds number (4 × 104–1.32 × 106), and equilibrium quality (?0.02–1.1). These tests report cryogenic chilldown data at the largest diameter lines ever reported. A total of 1,634 data points are added to the consolidated cryogenic chilldown database. Examination of both chilldown and boiling curves shows significant stratification in the larger diameter transfer line, even at highly turbulent Reynolds numbers. Higher inlet pressure always leads to faster chilldown times and higher heat transfer coefficients. Recently developed cryogenic quenching correlations are also compared with experimental results here to comment on the validity of applying the correlations to larger, longer transfer lines.
NSTL
Elsevier