The fluid mechanics and heat transfer in two-phase flow has always been a challenging matter. The consequences of the interaction between the liquid and the vapour phases provide the reasons for the application in a wide field of fluid systems. In the present work, the characterization of the liquid film distribution in horizontal two-phase annular flow has been investigated in order to understand its effect on the pressure drop and the heat transfer coefficient. This topic may be very important in the design of heat exchangers involved by two-phase flows with significant liquid film...