Visual Study of Resonance Dominated Microjet Flows Using Laser-Based Micro-Schlieren
Visual Study of Resonance Dominated Microjet Flows Using Laser-Based Micro-Schlieren
复制标题
使用基于激光的微纹影对共振主导的微射流进行可视化研究
DOI：
10.2514/6.2011-766
复制
发表时间：
2011
期刊：
影响因子：
2.5
通讯作者：
F. Alvi
中科院分区：
文献类型：
--
作者：
C. Foster;J. Solomon;F. Alvi
基于激光的微纹影系统已被开发出来，可以直观地分析高频脉冲微射流执行器、火花喷射执行器和 1 毫米冲击射流的不稳定微流场。由于这些流动的规模小且速度高，因此有必要开发一种具有高空间和时间分辨率的成像技术。在这项研究中，短持续时间光源与微纹影系统相结合。使用氩气中的激光诱导击穿作为光源，产生脉冲宽度约为 10 纳秒的宽带光，并设置图像的曝光时间。借助这种独特的光源，可以冻结这些小规模、高速、共振流中存在的结构。通过该技术，可以测量各种微尺度共振流的各种复杂流动特征，例如冲击振荡位移、射流前沿速度、气动声学结构之间的相位相关性等。
A laser-based micro-schlieren system has been developed to visually analyze the unsteady micro-flowfields of a high frequency pulsed microjet actuator, a sparkjet actuator, and a 1 mm impinging jet. Due to the small scale and high velocity of these flows it was necessary to develop an imaging technique that gives high spatial and temporal resolution. In this study, a short duration light source was coupled with a micro-schlieren system. Laser-induced breakdown in argon is used as the light source, which generates broadband light with a pulse width of approximately 10 nanoseconds and sets the exposure time for the image. With this unique light source, it is possible to freeze the structures present in each of these smallscale, high-speed, resonant flows. Through this technique various complex flow features such as shock oscillation displacements, jet front velocities, phase correlations between the aeroacoustic structures etc. were measured for various microscale resonant flows.