以火箭发动机燃烧室相变发汗冷却为背景,对水在流过横截面为50mmxl0mm的铜管中充满直径为0.4mm孔隙率为0.31的不锈钢珠多孔介质时沸腾换热现象进行数值模拟。研究了重力角度、无重力条件下多孔介质的导热系数以及内部缺陷对沸腾换热的影响。结果表明,重力角度、多孔介质导热系数及内部缺陷均影响多孔介质中的沸腾换热:重力与入口流呈0°时角度效应最大,近壁温度随导热系数的减小而降低,内部缺陷导致温度分布改变。
Based on the rocket combustors transpiration cooling process, a computational study has been conducted for water flowing through porous media as copper tubes of cross-section 50 × 10 mm filled with stainless steel beads of diameter 0.4 mm and porosity 0.31. The effect of gravity direction, thermal conductivity of porous media in non-gravity condition and internal defects on boiling heat transfer are investigated. The results showed that the boiling heat transfer in porous media is affected by inlet fiow direction, conductivity coefficient and internal defects: direction effect is maximum when inlet flow is parallel with gravity, conductivity coefficient decreasing can cause the temperature decreases near wall, internal defects significantly changes temperature distribution in the media.