Flow and heat transfer enhancement in condensing water drops in steam flows

摘要

Internal flow and heat transfer enhancement were experimentally and numerically investigated for 0.1- to 1-mm-sized water drops condensing in steam flows. The experimental data and computational fluid dynamics results are in agreement, showing that the external steam flow causes an internal flow in the drops via viscous shearing at the liquid-vapor interface. The velocity of the internal flow is only several percent of that of the external flow, but it enhances heat transfer by up to 117%. The effects of steam flow on heat transfer increase as the contact angle or the size of the drop increases.