PRESSURE-DROP IN GAS-LIQUID FLOW AT MICROGRAVITY CONDITIONS

A new set of experimental pressure drop air-water flow data at microgr avity conditions obtained aboard the NASA KC-135 aircraft is reported. Comparisons between pressure drop values at mu-g and l-g vertical upw ard how suggest that the forced convection two-phase flow frictional p ressure drop at microgravity is of the same order of: magnitude as tha t at normal gravity for otherwise the same tube geometry and flow cond itions. The main reason seems to be that the flow is mainly inertia do minated over the range of liquid and gas flow rates tested. The experi mental data were compared with several widely used empirical models, e .g. homogeneous model Lockhart-Martinelli method and Friedel's model. All models gave reasonable predictions.