边条翼布局双垂尾抖振的数值模拟

The numerical investigation of twin-vertical tail buffet of strake-wing configuration

对边条翼布局的双垂尾抖振进行了较为深入的数值模拟研究。模拟来流马赫数为0.2,迎角为10°-40°。通过非定常Euler方程计算各迎角下的非定常流场及垂尾根部弯矩系数。并将随时间脉动的根部弯矩系数进行计算得到根部弯矩系数均方根值,从而得出根部弯矩响应大小随迎角的变化曲线。结合流场特性对该布局双垂尾抖振的发生机理及抖振响应随迎角的变化规律作了深入分析。结果表明：该边条翼布局双垂尾抖振主要是由于边条破裂涡作用在垂尾上的脉动载荷引起的。最后,将垂尾根部弯矩响应的计算结果与该模型双垂尾抖振的风洞实验结果作了比较,结果符合得较好。

A time-accurate computational analysis of vertical tail buffet of strake-wing configuration at high angles of attack is presented. The model is pitched at a range of angles of attack from 10 to 40 degree, and at Mach number of 0.2. The aerodynamic flow field around the model is computed using the unsteady Euler equations. The pressure on the vertical tail surface is integrated to yield the root bending moment at each time step, then the Root Mean Square（RMS） value of the fluctuant root bending moment coefficient is computed, and the graph of RMS root bending moment coefficient vs angles of attack is presented. Combining with the flow field characteristic, the mechanism and characteristic of the twin-vertcial tail buffet of strake-wing configuration are disscussed. Results show that： the unsteady loads of vortex breakdown flow impinging on the vertical tail is the primary contributor of the vertical tail buffet. The computational results of the vertical tail buffet responses are validated and are in good agreement with experimental data.