By reviewing several publications on frictional pressure drop and interface drag in the two-phase flow of liquid metals, it is found that acceleration loss by droplets has a considerable effect on the hydraulic models, due to the high-density and the high-slip ratios. A one-dimensional, steady-state flow model is developed for vertical upward annular-dispersed flow under adiabatic conditions to account for acceleration loss by droplets. The results show that, if acceleration of droplets is considered, the two-phase multiplier and interface drag coefficient of the liquid film fall around correlations developed for ordinary fluids.