摘要
为估计M arangon i对流和自然对流对汽泡周围流场的影响,对加热面朝上和朝下的不同大小和过冷度的汽泡周围温度场进行了测量。通过比较测量所得温度场和带N av ier-S tokes方程的数值模拟结果可知,在完全没有浮升力时,M arangon i流会使得流场呈现一个向下的类似于射流的形状,但有了浮升力,向下的流动会立刻转向上,在加热表面附近形成涡流。即使加热面朝下,这种浮升力引起的自然对流依然影响整个流场,以至于这个系统不能很好地表现在微重力条件下的汽泡周围的流场。
The temperature distributions around vapor bubbles both on top of and underneath a heated surface were measured for different bubble sizes and different subcoolings to evaluate the effect of Marangoni flow and natural convection the flow field around vapor bubbles. Comparison of the measured temperature distributions to numerical solutions of the Navier-Stokes equations showed that even on the underside of a heated plate, the buoyancy of the heated flow significantly affects the overall flow field. Without buoyancy, the Marangoni flow should create a large plume downward from the bubble, but with buoyancy, the plume quiokly turns upward as the flow recirculates near the heated surface. Therefore, the buoyancy flow around a vapor bubble on the underside of a heated plate is significant enough that such a system is not an adequate representation of flows around vapor bubbles in microgravity where only Marangoni convection and evaporation/condensation induced flows are significant.
出处
《清华大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2006年第2期218-221,共4页
Journal of Tsinghua University(Science and Technology)
基金
国家教育振兴计划项目(081202300)
