高速聚焦纹影改进及应用

聚焦纹影技术能对垂直于光轴的特定平面内的流场细节进行显示,该特点使其成为近年来被重新研究的流场显示技术之一。本文在综合考虑了锐聚焦深度、非锐聚焦深度、灵敏度和清晰度等指标情况下,结合风洞实际情况,研制了一套聚焦纹影装置。主要在均匀照明流场、切割光栅的制作和不通过成像屏的高速相机直接记录等方面进行了改进工作,得到了较好的显示结果,并在小激波风洞上进行了相关的验证工作。同时,对采用聚焦纹影显示高速变化的流场也进行了探索,提出了相关的建议。

Improved high-speed focusing schlieren system and its application

Focusing schlieren technique can display the details of the specific plane perpendicu- lar to the optic axis in flow field. This characteristic makes it become one of the flow visualization technologies which have been restudied in recent years. In this paper, based on the comprehen- sive consideration of the indexes such as sharp focus depth, unsharp focus depth, sensitivity, res- olution and so on, and in combination with the practical situation of wind tunnel, we developed a set of focusing schlieren device. The device has made progress in the uniform illumination in flow field, the manufacture of cutting grating and high speed camera immediately recording without the imaging screen, which has got better visualization results, and the verification test has been done in the small shock wave wind tunnel. At the same time, we explored using focusing schlier- en to show the rapidly changing flow field and put forward some suggestions.