亚、跨、超声速下空腔流场特性实验研究

Experimental investigation of cavity flow characteristics at subsonic,transonic and supersonic speeds

在FL-21跨、超声速风洞中对空腔流场特性进行了较为深入的实验研究。空腔的长深比L／D为7、8、9、12、15，试验马赫数M范围为0．6、0．9、1．2、1．5、1．8，试验雷诺数Re为1．23～2．26×10^7。研究表明：空腔流场特性主要由空腔长深比L／D和来流马赫数所决定，这两个参数的变化均能引起空腔的流场类型发生变化。另外，边界层厚度δ对空腔底部的压力分布也有着显著的影响，随着边界层厚度与空腔深度之比d／D的减小，空腔的流场类型有向闭式穴流动转变的趋势。

An experimental investigation was conducted in FL-21 wind tunnel to study cavity flow characteristics. Cavities were tested over length-to-depth ratios of 7, 8, 9, 12, 15. The test range of Mach number was from 0.6 to 1.8, and the test range of Reynolds number was from 1.23 × 10^7 to 2.26 × 10^7. The results show that the changes of cavity length-to-depth L/D and Mach number have dominant effect on cavity flow characteristics, and the variety of L/D and M can cause the change of the cavity flow field type. Moreover, it indicates that the change of boundary layer thickness ~ also influences cavity floor pressure distributions markedly, and the cavity flow type will tend to close type with the reduction of the ratios of boundary layer thickness to cavity depth δ/D.