湍动能模拟内部声激励的计算研究

Computational Research on Internal Acoustic Excitation by Using Turbulence Kinetic Energy Analogy

为了研究襟翼表面的声激励对多段翼型升力特性的影响机理,利用湍动能假设进行数值计算研究。以湍动能的量值、雷诺数以及襟翼与主翼的搭接量为参数,研究上述参数的变化对升力特性的影响,得到的结果与实验值符合良好。在多段翼型缝道处加入湍动能的影响规律是:(1)在升力特性线性段减少了升力系数,在失速点附近可以推迟分离,提高升力系数;(2)当雷诺数增加时,湍动能对升力系数的影响量减小;(3)在搭接量为零时,湍动能的影响最大。上述规律与在缝道处加入声学激励的影响规律一致,表明采用注入湍动能来类比声学激励有一定的应用价值。

In order to study the effects of acoustic excitation on a multi-element airfoil performance,a computational method is provided,which uses an assumption that turbulent kinetic energy can be a good analogy of acoustic excitation.The results show that acoustic excitation can affect the aerodynamic characteristics of airfoil when changing some conditions,which including the magnitude of turbulent kinetic energy,the Reynolds number,the gap between flap and wing.The simulation results are in accord with the experimental results.Results of using turbulent kinetic energy assumption on a multi-element are as follows：（1）The lift in linear area of airfoil is reduced,it can delay separation around the stall point,and the lift is improved.（2）When the Reynolds number is increased,the turbulent kinetic energy will reduce the effect on lift.（3）When the overlap equals zero,the effect on lift is the largest.These computational requests are in good agreement with wind tunnel experiment in qualitative analysis.It is confirmed that the analogy is a good approach to be used.