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声爆精确预测及低声爆设计方法已成为新一代军民用超声速飞机研制过程中必须解决的关键难题之一。基于计算流体力学(CFD)、波形参数法以及MARK-VII方法构建了高精度声爆预测方法,利用该方法对低声爆静音锥的设计展开研究。研究结果表明,静音锥的设计存在临界长度,静音锥长度小于临界长度时,静音锥产生的激波在传播过程中与机头弓形激波合并,静音锥无法起到降低声爆的作用;静音锥长度大于临界长度时,声爆水平也会略有上升。静音锥临界长度随飞行高度和飞行马赫数的变化而变化,可以根据实际飞行状态采用可伸缩设计,达到最佳的低声爆效果。多级静音锥利用多道弱激波取代机头强弓形激波,其声爆水平较单级静音锥也更低,同样,多级静音锥每一级的长度也要达到临界长度。不同静音锥头部形状产生的脱体激波形状不同,脱体距离也不同,导致阻力系数以及静音锥壁面温度有所不同,但静音锥头部形状对远场声爆信号的影响并不明显。采用静音锥的低声爆方案与原始方案比较,声爆水平得到大幅降低,阻力系数略有上升。
The precise prediction of sound explosion and the design method of low sound explosion have become one of the key problems that must be solved in the development of a new generation of military and civilian supersonic aircraft. Based on Computational Fluid Dynamics (CFD), waveform parameter method and MARK-VII method, a high-precision acoustic explosion prediction method is constructed. The design of low-noise explosive mute cone is studied by this method. The results show that there is a critical length in the design of mute cone. When the mute cone length is less than the critical length, the shock wave generated by the mute cone merges with the bow shock during the propagation. The mute cone can not reduce the sound explosion; the mute When the length of the cone is greater than the critical length, the sound explosion level will rise slightly. Mute cone critical length with the flight altitude and flight Mach number changes, according to the actual state of the flight using retractable design, to achieve the best low sound explosion effect. Multistage mute cone Multi-channel weak shock to replace the machine bow arched shock burst sound level than the single-stage mute cone is also lower, the same multi-stage mute cone length of each stage to achieve critical length. The shape of the shock wave generated by different mute cones is different in shape and the separation distance is also different, which leads to the different drag coefficient and the wall temperature of the mute cone. However, the shape of the mute cone has no obvious effect on the far-field sound explosion signal. . Compared with the original scheme, the sound explosion level was greatly reduced and the drag coefficient increased slightly.