湍动能模拟内部声激励的计算研究

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。

Computational Research on Internal Acoustic Excitation with Turbulence Kinetic Energy Analogy

A series of experiments on acoustic excitation on a multi-element airfoil performance were conducted in NF-3 wind tunnel in 2008. The results showed that internal acoustic excitation can change the aerodynamics characteristics of the airfoil under some conditions. This paper provides a computational method,which uses an assumption that turbulent kinetic energy can be a good analogy of acoustic excitation in study the effects of using internal acoustic excitation. Results of computation by solving 3D RANS are as follows:(1)The turbulent kinetic energy deduced lift in linear area of the airfoil by -2%(max) and improved lift around stall point by 5%(max);(2)The change on lift is smaller when the Reynolds number is higher;(3)When the O/L equals zero,the change on lift is the maximal one. These computational results are in good agreement with wind tunnel experiment in qualitative analysis. This paper confirms that the assumption of turbulent kinetic energy will be a nice expected approach to analogy of internal acoustic excitation.