摘要
为了解绕圆头回转体通气超空化的流场特性,采用数字式粒子图像测速(PIV)系统和高速全流场显示技术,观测了绕圆头回转体通气超空化的空泡形态发展变化过程和尾迹流场。研究结果表明:在通气超空化空泡发展的整个过程中,空泡区域内前部流场比较平稳,为稳定的透明气相区;空泡尾流区域出现气相和水气两相混合区且存在显著的旋涡结构,此旋涡结构与主流相互作用产生大尺度的脱落空泡团,最终形成超空化尾迹。与不通气相比,通气超空泡化产生的脱落空泡团对回转体尾流区域流场影响较大,使尾迹区低速区域的范围明显增大,且低速区域内各个剖面上的速度明显减小;上下涡量带随着空泡区域的延伸而向后拉长,作用范围亦逐渐扩大,涡量聚集区由最初的涡量带转化为多个分散的涡量团,并逐渐向下游耗散。
To understand ventilated supercavitating flows around a hemisphere cylinder, the unsteady process of development of ventilated supercavity and the flow field of wake around a hemisphere cylinder are observed by means of a digital particle image velocimetry system and a high speed video camera. The results show that a steady transparent air area is observed near the foreside of the ventilated supercavity in the process of development of ventilated supercavity, and there is a vortex in the rear of supercavity. Water and air mixed area is full of the rear part, and finally bubble shedding in large scale appears, which has great effect on the flow field at the rear of a hemisphere cylinder. Compared to no-ventilated conditions, the range of low velocity area in the wake obviously expands, and the velocities of measuring points in various profiles decrease. The upper and lower velocimetry ropes stretch backward and enlarge by degrees as the ventilated cavity region extends rearward, becoming many dispersed velocimetry groups that gradually dissipate downstream.
出处
《兵工学报》
EI
CAS
CSCD
北大核心
2014年第4期475-483,共9页
Acta Armamentarii
基金
国家自然科学基金项目(11172040)
关键词
流体力学
通气超空化
数字式粒子图像测速系统
空泡脱落
fluid mechanics
ventilated supercavity
digital particle image velocimetry system
bubble shedding
