【摘要】 以去离子水为工质,在大气压下针对倾斜矩形结构开展了倾斜窄缝空间内池式沸腾汽泡行为的可视化试验研究。加热表面倾角从0o变化到30o,矩形窄缝尺寸从3 mm变化到8 mm。研究表明,窄缝结构和加热表面下朝向是产生"孤立变形汽泡"、"聚合变形汽泡"和"局部干涸"等3种流型的主要原因。以无量纲热流密度数Q和窄缝尺寸与汽泡脱离直径之比Bo数绘制出了Q-Bo关系曲线,确定了流型转变的过渡准则式。当Bo>1时,孤立变形汽泡区与聚合变形汽泡区的过渡准则大致为Q=0.16,聚合变形汽泡区与局部干涸区的过渡准则大致为Q=0.55。更多还原

【Abstract】 In this paper,visualization of bubble behavior and two-phase flow in inclined confined spaces are performed for near-saturated demineralized water at atmospheric pressure with gap sizes of 3mm to 8mm,and inclination angles of 0° to 30°.Based on the results,three boiling regimes are observed:isolated deformed bubbles,coalesced deformed bubbles and partial dry-out.A flow pattern map for confined pool boiling,based on the Bond number and a dimensionless number of heat flux,has been developed in order to determine the regimes.Objective criteria are proposed for the transitions between various regimes.It is shown that the transition criteria between isolated deformed bubbles and coalesced deformed bubbles is Q=0.16 and Q=0.55 between coalesced deformed bubbles and partial dry-out.It has to be pointed out that the gap structures and downward facing heating surfaces may be responsible for the special flow patterns更多还原