Interfacial-Area Transport Equation at Reduced-Gravity Conditions

Abstract

The interfacial-area transport equation is of practical importance for two-phase flow analyses at reduced-gravity conditions. In view of this, the interfacial-area transport equation, which takes the gravity effect into account, is studied in detail. The constitutive equation for the sink term of the interfacial-area concentration due to wake entrainment has been developed by considering the body acceleration due to frictional pressure loss. A comparison of the newly developed interfacial-area transport equation with various experimental data taken at normal-gravity and microgravity conditions shows a satisfactory agreement. An example computation of the newly developed interfacial-area transport equation has been performed at various gravity conditions such as 0, 1.62, 3.71, and 9.80 m/s 2 , which correspond to zero-gravity and the lunar, Martian, and Earth surface gravities, respectively. It has been revealed that the effect of the gravity on the interfacial-area transport in a two-phase flow system is more pronounced for low-liquid-flow and low-void-fraction conditions, whereas the gravity effect can be ignored for high-mixture-volumetric-flux conditions.