摘要
采用NS方程对激波诱导球形轻气泡的变形失稳过程进行三维数值模拟,验证本文模型的可靠性,讨论气泡变形、涡环形成及其三维失稳过程.结果发现:球形轻气泡在入射和反射激波先后作用下,可以变形并沿流向形成多个旋转方向不同的涡环,而斜压效应是产生这些涡环的主要原因,涡环不仅在自诱导效应和流场作用下运动,而且自身会受到扰动而发生方位角不稳定.当涡环形成以小尺度流向涡为主的复杂结构时,即有可能诱发流场湍流化.
A three-dimensional simulation on deformation and instability of low-density spherical bubble induced by incident and reflected shock waves is performed with Navier-Stokes equations.A computational model validated by experiments is used to study deformation of bubbles,formation and three-dimensional instability of vortex rings.It is found that low-density spherical bubbles can deform and form vortex rings with different rotating directions along streamwise direction induced by incident and reflected shock waves.Baroclinic effect is the main reason for formation of vortex rings.Vortex rings move due to self-induced effect and flow field velocity.And azimuthal instability occurs due to disturbance.Finally,vortex rings may induce turbulent flow as they form a complicated structure dominated by small-scale streamwise vortices.
出处
《计算物理》
EI
CSCD
北大核心
2011年第6期810-816,共7页
Chinese Journal of Computational Physics
基金
国家自然科学基金(10972107)资助项目
关键词
激波
斜压效应
涡量
涡环
方位角不稳定
shock wave
baroclinic effect
vorticity
vortex ring
azimuthal instability
