中文摘要：

武器内埋是实现战斗机超声速巡航、低可探测性（隐身）等先进技术指标的关键气动布局措施之一。腔内流场结构复杂,在一定条件下存在严重压力脉动,诱发强烈噪声,声压级（SPL）甚至可高达170dB,可能造成结构与内部元器件的破坏,因此空腔噪声与抑制方法成为研究热点之一。为此,对亚、跨声速流动条件（Ma=0.6、0.95和1.2）下有、无斜劈（ramps）时过渡式空腔（长深比L/D=4）气动声学特性开展了风洞试验研究,通过综合对比分析空腔底面中心线上的声压级分布和不同测点的声压频谱（SPFS）特性,探讨了斜劈对空腔气动噪声的抑制效果。研究结果表明,在亚、跨声速条件下,采用前缘斜劈对空腔内噪声有一定抑制效果,使得空腔后部区域声压级降低幅度比前部区域大,同时对空腔前壁以及后壁噪声也有抑制效果,部分典型测点声压频谱曲线上的能量尖峰基本全部被削平,这表明空腔流场已不存在产生自持振荡的流动机制。

英文摘要：

Weapons embedding is the key technique to achieve the advanced aerodynamic characteristics and stealthy performance for the supersonic cruising fighter.The flow in the weapon cabin is very complex and the sound pressure level of strong noise induced by strong fluctuant pressure is as high as 170 dB which may damage the cabin＇s structure and the interior facilities,so the cavity noise generation and its corresponding suppression become the hot research topics.This paper presents a brief analysis of the aero acoustic characteristics in a cavity of length-depth ratio（L/D）of 4with and without leading edge ramps under sub-and transonic conditions（Mach number is 0.6、0.95 and 1.2）.The suppression effects of the ramp on aerodynamic noise are discussed by analyzing the sound pressure level distribution on the centerline of the cavity floor and the sound pressure frequency spectrum（SPFS）characteristics at different measurement points.The results show that the leading edge ramps can suppress aerodynamic noise inside the cavity both at the floor and at the sidepiece and it is more effective in SPL reduction in the rear range of the cavity than in the front.The energy peaks of SPFS at some measurement points almost disappeared with the leading edge ramps which indicate that the flow mechanism of self-sustained oscillation disappeared.