Flow regime transition criteria for two-phase flow at reduced gravity conditions

► Extensive review of existing flow regime transition model and datasets. ► Flow regime transition criteria proposed for reduced gravity condition. ► Acceleration due to frictional press loss considered for actual body acceleration. ► Computation performed at microgravity, lunar, Martian and Earth gravity conditions. ► Gravity effect on bubbly-slug, slug-annular, and annular transitions studied.