Thermal and flow characteristics of evaporating capillary pore flows ranging from 10-mm to 10-mu m diameter

摘要

Flow and thermal characteristics are studied for capillary pore cavities with free surfaces ranging from 10-mm to 10-mum diameter. Also the effect of micro gravity is investigated. A standard finite volume method (FVM), in association with the well-established boundary-fitted coordinate transformation (BFCT), is used to numerically solve the governing equations for primitive scalar variables of velocity components, pressure and temperature. Calculation results show that the convection-driven circulation and the thermocapillary phoresis effect dominate the flow and thermal fields of larger pores, bigger than 1.0-mm diameter. With decreasing pore diameter, the flow circulation diminishes and the interfacial evaporation dominates to establish nearly stratified flow patterns parallel to the pore wall. Micro-scale capillary pores, less than 1.0-mm diameter, show no flow circulation with almost horizontally stratified temperature fields. Micro gravity condition shifts this transition which is from convection-driven to interfacial flow dominated flow regime to bigger pore diameter.