阵风响应及减缓的非定常数值模拟

Gust Response and Alleviation Analysis of Airfoil

基于网格速度和动网格方法,通过求解非定常N-S方程计算翼型副翼偏转时的阵风减缓响应,研究开环控制律参数和副翼缝隙对阵风减缓效果的影响。对于单个1-cos阵风,随着偏转角度的增大,减缓效果变大;由于粘性的影响,CFD计算得到的升力峰值减小量明显呈非线性的趋势,减缓效果低于准定常线性理论。对于连续sin阵风,通过调整副翼偏转的频率和最大偏转角,升力能达到很好的减缓效果,此时,副翼偏转频率应接近阵风频率,最大偏转角存在一个最优值。在阵风环境下,副翼间隙对升力系数影响不大,而力矩系数增大一倍,间隙会降低副翼偏转对升力的减缓效果。

The field velocity method is used to calculate gust response of airfoil by solving unsteady N- S equation, and gust alleviation response is also calculated with the dynamic grid method. The effect of open - loop control parameter and aileron gap is studied. The 1 - cos gust response analysis of airfoil is performed, the alleviation results becomes better while the aileron rotates larger. The max lift response calculated by CFD tool is less than the quasi- steady linear results due to the viscous affects. The continuous sin gust response of airfoil is calculated, the lift will reduce much if aileron rotate at a given frequency and given maximum rotating angle. In gust environment, aileron gap affects little to the lift response, while moment coefficient doubles, the aileron gap reduces the alleviation effect of the airfoil.