弹体脉动压力特征的实验研究

针对弹体模型进行了表面脉动压力特性实验研究,实验马赫数M∞=0.8、0.84、0.86、0.92、1.0、1.15、2.0、2.5,实验迎角α=-5°、-3°、0°、3°、5°,沿弹体轴向测量了14个特征点的脉动压力,得到了弹体表面测点的脉动压力系数、频谱曲线以及相关性系数等实验数据。结果表明:脉动压力系数总体上随马赫数增加而降低。不同马赫数,迎角α=0°的条件下沿轴向各测点压力脉动之间的空间相关性有类似的分布规律,且各测点脉动压力基本互不相关。在实验的迎角下,脉动压力系数在弹体表面曲率变化较小的位置基本上不随来流迎角的改变而变化,膨胀拐角肩部位置的脉动压力系数随着迎角的改变而变化较大。超声速来流的功率谱能量峰值所对应的主频出现明显的低频特征;跨音速来流时特征频率随着马赫数的增加而增大,功率谱能量峰值位于特征频率处。

Experimental research of fluctuating pressure on surface for a certain missile configuration

The characteristics of fluctuating pressure for a certain missile configuration are studied. The Mach number is M∞=0.8,0.84 , 0.86, 0.96, 1.0,1.15, 2.0, 2.5, and the angle of attack is α=-5°、-3°、0°、3°、5°, there were 14 testing holes on the surface along the axes of this missile configuration.Dtailed information for fluctuating pressure coefficient, power spectrum density and spatial correlation has been acquired.The results of the experiment indicate that the fluctuating pressure coefficient reduced with the Mach number increasing.The fluctuating pres-sure has the similar axial cross correlation for any two of the testing points along the axes of this missile configuration at different Mach number.The aixal cross correlation for different testing points along the axes of this missile configuration at zero angle of attack can be neglected.In the range of angle of attack, different angle of attack has little influence over the fluctuating pressure coefficient in the region of small curvature changes.The fluctuating pressure coefficient varies obviously under different angle of attack in the region of remarkable curvature changes.The pow-er spectrum density shows that the character frequency is obvious low at supersonic, and the character frequency increases with the Mach number increasing, and the maximum power spec-trum density located at the location of character frequency.