水中开孔腔流激振荡控制实验研究  

EXPERIMENTAL INVESTIGATION INTO THE CONTROL OF FLOW-INDUCED OSCILLATIONS OF UNDERWATER APERTURE-CAVITIES

作　　者：章文文 徐荣武 何琳[1] 潘龙德 赵佳锡 Zhang Wenwen;Xu Rongwu;He Lin;Pan Longde;Zhao Jiaxi(Institute of Vibration and Sound,Naval University of Engineering,Wuhan 430033,China;Aerodynamic Noise Control Key Laboratory,China Aerodynamics Research and Development Center,Mianyang 621000,Sichuan,China)

机构地区：[1]海军工程大学振动与噪声研究所,武汉430033 [2]中国空气动力研究发展中心气动噪声控制重点实验室,四川绵阳62100

出　　处：《力学学报》2021年第10期2762-2775,共14页Chinese Journal of Theoretical and Applied Mechanics

基　　金：国家自然科学基金资助项目(11904407)。

摘　　要：水中开孔腔流激振荡是水下航行器的一类突出噪声源.为探究有效抑制水中开孔腔流激振荡的控制方法和作用特性,首先以水下航行器的表面开孔结构为对象设计了开孔腔模型,并提出一种基于来流边界层分流原理的流动控制装置——前缘分流体,借助循环水洞装置对水中开孔腔的流激振荡特性及其控制进行了实验研究.通过沿流向和展向安装于腔底的动态压力传感器测量腔内脉动压力,分别从腔内脉动压力的频谱特性和空间分布特性两方面,探讨了水中开孔腔在不同流速下的流激振荡特性和前缘分流体对水中开孔腔流激振荡的控制效果,并对前缘分流体的主要作用机理进行了分析.研究结果表明:水中开孔腔流激振荡形式以剪切层自持振荡为主,在流速较低时,如2.4 m/s,就会产生稳定的自持振荡,且具有随流速升高而急剧增大的趋势;前缘分流体对水中开孔腔绕流自持振荡具有良好的抑制效果,且抑制效果随流速增加而显著提升,对腔内脉动压力频谱峰值和总级的最大抑制量分别达到25.3 dB和15.6 dB;此外,前缘分流体对开孔腔流激振荡具有低频频移作用,有益于避免发生流激空腔共振;脉动压力空间分布特性表明,前缘分流体对水中开孔腔流激振荡抑制机理主要在于破坏了腔内流场受到的周期调制作用.Flow-induced oscillation(FIO)of underwater aperture-cavities is one of prominent noise sources of underwater vehicles.In order to explore the effective control method and suppression characteristics of FIO of underwater aperture-cavity,experiments of FIO characteristics and its control of underwater aperture-cavities were carried out in the circulating water tunnel.The experimental model of underwater aperture-cavity was designed based on the surface aperture structure of underwater vehicles,and the FIO control device,leading-edge flow splitter(LFS),was proposed based on the principle of incoming boundary layer diversion.The FIO characteristics of underwater aperturecavities and the effects of LFS on FIO at different freestream velocities were discussed from the two aspects of the frequency spectrum characteristics and the spatial distribution characteristics of the intracavity pressure fluctuations,while the intracavity pressure fluctuations were measured by the streamwise and spanwise installed dynamic pressure transducers at the bottom of the cavity.The investigation results show that the form of FIO of underwater aperturecavities is dominated by the self-sustained oscillation of the shear layer,which occurs at a relatively low freestream velocity,such as 2.4 m/s,and has an intensive reinforcement with the increase of the freestream velocity.It was proved that the LFS has a good suppression effect on the FIO of aperture-cavities in water,and the suppression effect is significantly enhanced with the increase of the freestream velocity.Specifically,the maximum suppression of the peak and total level of the intracavity pressure fluctuations spectrum reaches 25.3 dB and 15.6 dB,respectively.Besides,the LFS has a low frequency shift effect on the FIO of aperture-cavities,which is beneficial for avoiding the occurrence of flow-induced cavity resonance.Finally,the spatial distribution characteristics of pressure fluctuations indicate that the suppression mechanism of the FIO of underwater aperture cavities by the LFS

关 键 词：开孔腔 流激振荡 流动控制 空腔流动 水下噪声 

分 类 号：O352[理学—流体力学]