过冷流动沸腾汽泡凝结变形及流场特性的数值模拟

Numerical investigation of bubble deformation and flow field characteristics of subcooled boiling during condensation

建立了过冷流动沸腾汽泡凝结质量及能量传递模型,采用VOF多相流模型,对汽泡凝结过程进行了数值模拟。得到了不同工况下汽泡变形过程及其内部和周围流场变化,与前人研究结果吻合较好。结果表明:汽泡凝结过程中,其形貌将发生变化且受汽泡初始直径和过冷度等影响显著。过冷度越高或初始直径越大,汽泡变形越剧烈。当初始直径和过冷度都达到一定数值时,汽泡在凝结后期将发生破裂。

The mass and energy transfer model of bubble condensation in subcooled boiling flow is established.The bubble condensation process is numerically simulated by VOF model.The bubble deformation and flow field characteristics are also obtained.The result agrees well with previous results.The results indicate that bubble shapes will change and are significantly influenced by the bubble initial diameter and the subcooled degree in condensation process.The bubble deformation will appear more sharply with increasing subcooled degree or initial diameter.The bubble will break when the subcooled degree and initial diameter reach a certain value at later phase.