Void fraction correlation for vertical and horizontal bulk-boiling of water

Void-fraction data from three sources, obtained by three experimental methods, have been correlated semiempirically. Assuming a continuous transition from bubbly to separate flow, an equation has been derived, expressing void fraction as a function of; density ratio of the phases, the quality, and the void fraction at the transition point from bubbly to churn or slug flow. This void fraction is 0.302 for all the data. The equation applies to water-air adiabatic and to water-steam diabatic systems inside round tubes, at pressures from atmospheric to 14480 kN/m2, and qualities from 0.001 to 0.5. (U.S.)