リブ付き偏平流路内の気液二相流の流動特性 : 垂直上昇流および下降流

抄録

The purpose of this study is to clarify the effects of transverse ribs and cross ribs in a narrow channel (interwall spacing is 2∼3mm) on two-phase flow characteristics and pressure drop as a part of heat transfer improvement of a plate-fin evaporator. The flow configuration, spanwise local void fraction and pressure drop were investigated for various liquid and gas velocity conditions, using an air-water mixture as the working fluid. In the smooth and transverse-ribbed channels, liquid tends to deviate to both sides of the channel. This fact is not considered preferable for evaporative heat transfer performance. To the contrary the cross-ribbed channel has a notable effect of dispersing liquid uniformly in the spanwise direction. The pressure drop data for each channel are correlated well in the form of ΔP_f/ΔL∝Re^*n for both upward and downward flow by using nonly one parameter of the equivalent Reynolds number Re^*.