Flow over a flat plate with a 5% thickness ratio is investigated by schlieren visualization in compressible low-Reynolds-number conditions. The results show that flow separates at the leading-edge and laminar separation-bubble forms. The position of the maximum root mean square of the schlieren image which is related to the position of the vortex shedding moves downstream as a Mach number increases. Furthermore, the two-dimensional structure of generated vortices is maintained up to the trailing edge at the Mach number of 0.66. The frequency analysis of the time-series intensity value of the schlieren images also shows that the flow is stabilized with increasing the Mach number. The position of the end of the pressure plateau region matches the position where the root-mean-square value of the intensity image becomes a maximum due to vortex shedding.

在可压缩的低雷诺数条件下，通过纹影可视化研究了厚度比为 5% 的平板上的流动。结果表明，流动在前缘分离和层流分离-气泡形式。随着马赫数的增加，纹影图像的与涡旋脱落位置相关的最大均方根的位置向下游移动。此外，生成的涡流的二维结构一直保持到马赫数为 0.66 的后缘。纹影图像的时间序列强度值的频率分析也表明，随着马赫数的增加，流动是稳定的。