涡流管非稳态旋流流场数值模拟研究

Numerical study of transient swirl flow characteristic in Ranque-Hilsch vortex tube

中文关键词: 涡流管  强旋流 非稳态  数值模拟 涡旋破碎

英文关键词: vortex tube  strong swirl flow  transient or unsteady  numerical simulation  vortex breakdown

中文摘要:

      旋流主导着涡流管的内部流动,在有旋流的设备当中,高强度旋流由于涡旋破碎诱导产生的位于中央回流面附近的进动涡核被认为是旋流中的一种拟序结构,可以在一个峰值频率下偏离管道中心并绕着轴线做周期性运动,这种流动结构的产生对旋流本身产生了极大的影响。采用非定常求解模式计算三维涡流管内的内部流场, 雷诺应力模型用于封闭Navier-Stokes输运方程,在FLUENT 15.0中数值模拟计算涡流管的内部旋流。结果显示了涡流管瞬态旋流速度场中的周期性振荡,以及非对称大尺度涡结构。

英文摘要:

      The swirl flow dominates the flow field in the vortex tube, however the study about the swirl characteristics is seldom studied. In other devices where the swirl flow also occurs, the vortex breakdown in the high intensity swirl flow can inspire the precessing vortex core (PVC), locating around the central reverse flow zone. The PVC is regarded as a coherent structure in swirl flow, which deviates the tube center, precesses the tube axis and have a great impact on the swirl flow. An unsteady three-dimensional model was adopted. Reynold Stress Model was applied to the Navier-Stokes transport equation. The numerical simulation was performed on FLUENT 15.0 to study the swirl flow in the vortex tube. The results shown the periodic oscillation in the transient velocity field and the asymmetric large-scale vortex structure.