Liquid film circumferential asymmetry prediction in horizontal annular two-phase flow

► New method to predict liquid film asymmetry in horizontal annular two-phase flow. ► Large underlying experimental database (1276 local film thickness measurements). ► Disturbance waves counterbalance gravitational settling in liquid film. ► New prediction method based on Froude number and two empirical constants. ► Existing horizontal flow maps updated to include symmetric/asymmetric annular flows.