A Numerical Study of the Effect of Contact Angle on the Dynamics of a Single Bubble During Pool Boiling

Abstract

The effect of contact angle on the growth and departure of a single bubble on a horizontal heated surface during pool boiling under normal gravity conditions has been investigated using numerical simulations. The contact angle is varied by changing the Hamaker constant that defines the long-range forces. A finite difference scheme is used to solve the equations governing mass, momentum and energy in the vapor and liquid phases. The vapor-liquid interface is captured by the Level Set method, which is modified to include the influence of phase change at the liquid-vapor interface. The contact angle is varied from 1° to 90° and its effect on the bubble departure diameter and the bubble growth period are studied. Both water and PF5060 are used as test liquids. The contact angle is kept constant throughout the bubble growth and departure process. The effect of contact angle on the parameters like thermal boundary layer thickness, wall heat flux and heat flux from the microlayer under various conditions of superheats and subcoolings is also studied.