摘要
利用纹影方法和高速摄影得到了高速冲击射流在不同压比下的流场结构,发现在马赫盘出现之前,冲击射流的流场是整体振荡的;而马赫盘出现之后,冲击射流的流场振荡局限于马赫盘与冲击平板之间,且此时离散频率的冲击单音也明显减弱甚至消失,这意味着马赫盘的形成可一定程度地抑止反馈环的形成。
In the paper, flow structures at different pressure ratios are obtained by Schlieren image and high speed camera. It is found that the whole flow field is oscillating at lower pressure ratio. When Mach disk forms in the flow field, the oscillation will only exist between Mach disk and impinging plate. At the same time, impinging tone with discrete frequency will be decreased and even be diminished. From this point, it can be deduced that Mach disk can restrain the formation of feedback loop for discrete frequency impinging tone.
出处
《流体力学实验与测量》
CSCD
北大核心
2003年第2期84-87,共4页
Experiments and Measurements in Fluid Mechanics
基金
国家自然科学基金资助项目(批准号:19902009)
关键词
冲击射流
流场结构
马赫盘
反馈环
噪声
自激振动
impinging jet
Mach disk
discrete frequency impinging tone
feedback loop
