三维陷落腔脉动压力分布特性实验研究

Experimental research on fluctuating pressure distribution of 3D cave-in cavity

文章针对均匀流场中三维深型陷落腔因流分离而产生的流激振荡问题开展了一系列的实验研究。在来流流速为0攻角时实验时的雷诺数变化范围:Re=1.55×105～8.74×105。实验中分别测量了三维深型陷落腔侧壁周向及垂向流体压力,分析了腔体内脉动压力周向、垂向的分布规律及腔口处剪切层自持振荡特性。实验结果表明:均匀流场中三维深型陷落腔内脉动压力分布较为复杂。在剪切层随边处的脉动压力最大,随边角点处脉动压力随相对高度的增加而陡降为0,但腔口导边及侧面处的脉动压力随相对高度增加而略有增大。剪切层自持振荡频率的无量纲数St数随Re变化为一常数值,但其值比气流场中二维陷落腔的St数略大。

Aiming at fluid induced oscillation problem of 3D cave-in cavity owing to separation flow in uniform,a series of physical experiments was carried out.The range of Reynolds number is Re=1.55e^5～8.74e^5 at zero attack angle of incoming.Circumferential and vertical fluid fluctuating pressures along the deep cavein cavity were measured,meanwhile,distribution of fluctuating pressure and oscillation characteristic of shear layer were analyzed.The results of experiment show that the distribution of fluctuating pressure in uniform field is complex.The fluctuating pressure at the leading edge of shear layer is the largest and fluctuating pressure at angular point drops to zero with the relative height increasing.But the fluctuating pressures at the leading edge and side increase a little with the increment of relative height.Moreover the change of St number of shear layer versus Re number is constant,but the value of St number is larger than the value of two dimensions in the air.