FLUID FLOW AND HEAT TRANSFER IN A RADIALLY SPREADING THIN LIQUID FILM

Abstract

Improvements in the theoretical model and computational procedure for the prediction of film height and heat transfer coefficient of the free surface flow of a radially spreading thin liquid film adjacent to aflat horizontal surface of finite extent are presented. Flows in the presence and absence of gravity are considered. Theoretical results are compared to available experimental data with good agreement. In the presence of gravity, a hydraulic jump is present, isolating the flow into two regimes: supercritical upstream from the jump and subcritical downstream. In this situation, the effects of surface tension are important near the outer edge of the disk where the fluid experiences free fall. A region of flow separation is present just downstream of the jump. In the absence of gravity, no hydraulic jump or separated flow region is present. The variation of the heat transfer coefficient for flows in the presence and absence of gravity is also presented.