矩形微通道中环状冷凝的数值模拟

SIMULATION FOR ANNULAR CONDENSATION FLOW IN RECTANGULAR MICROCHANNELS

建立了一套恒热流边界条件下矩形微通道内环状冷凝过程的一维稳态模型,进行了数值计算,并将数值模拟结果与正三角形中的冷凝过程进行了比较.研究显示,在不同截面的微通道中,液相毛细半径和流速的沿程变化趋势都是相似的.同条件下。矩形通道的冷凝段长度大于正三角形通道.在矩形微通道中,通道入口蒸气压力和水力直径越大或者接触角越小,则冷凝段长度越长。

A one dimensional model for steady annular condensation flow in rectangular microchannels was developed and solved under constant heat flux condition. The simulation results were compared with what in triangular microchanneis. The trends of the curvature radius and liquid flow speed distribution in different cross shape channels are almost the same; however, the condensation length in rectangular microchannles is longer than what in triangular channels under the same condition. The annular condensation length is determined by the contact angle, the heat flux, the steam pressure and the hydraulic diameter of the channel. A larger steam pressure and hydraulic diameter or a smaller contact angle will result in a longer condensation length.