细长体大攻角非对称流动的声激励控制方法研究

detailed investigation was conducted on the flow asymmetry and its influencing factors over an ogive slender body model, incorporated with surface pressure measurement, skin oil flow pattern visualization, hot wire dynamic signal acquasition and other relevant approaches. Based on these, the present paper investigates in turn manipulating method using acoustic excitation, and explores evolution physics of the flow asymmetry over the slender body at high angles of attack in low and subsonic speed flow..The present study shows that the acoustic excitation can affect the flow asymmetry occurring on the high-alpha slender body by affect the stability of the leeward flow. Acoustic excitation enables to obviously improve the asymmetric behaviors as long as controlling conditions are chosen appropriately. The controlling effectiveness is the most apparent under the case that the excitation location is located near the first separated flow region, and the excitation frequency approaches the inherent frequency and its harmonic frequency of the first separated flow region near the nose.Along with the result of variations of grit type and external acoustic ,we studied the evolution physics of the flow asymmetry over the slender body at high angles of attack., and exhibits some evidences to prove the flow spatial instability as a cause of the flow asymmetry.

大攻角流动非对称性是当今空气动力学的重要问题。初步分析表明，声激励是一种极具潜力的大攻角非对称流动控制方法。本项目通过低速和亚音速风洞试验，综合脉动速度的频谱分析、表面测压和流动显示，探讨声激励对细长体大攻角非对称流动的作用机理，考察各种激励参数的控制效果，从而探索一种具有高增益的飞行器前体大攻角非对称流动控制方法。通过揭示大攻角流动非对称性控制的物理机制，为发展大攻角流动非对称性控制理论提供依据。