An experimental study and prediction of a two-phase pressure drop in microgravity

Experimental two-phase pressure drop results obtained in normal gravity and in nearly zero-gravity aboard a NASA-JSC reduced-gravity KC-135 aircraft are used to evaluate several empirically based correlations and flow-regime dependent models. Pressure drops in reduced gravity and those in normal gravity are shown to be related to flow pattern models for each. Two annular flow models are developed which are found to accurately predict the reduced-gravity data.