联翼布局俯仰力矩非线性变化特性的数值模拟

联翼布局飞机具有优良的升阻特性,是下一代亚声速飞机优先选择的气动布局型式之一,但在某些情况下其俯仰力矩随迎角的增大会表现出较强的非线性变化特点.针对该问题,在Ma=0.75条件下,采用数值模拟方法对某亚声速联翼布局气动性能及其绕流流场进行研究,通过对各部件气动特性分析,结合不同前翼绕流流动状态下前/后翼绕流场特点及截面气动力分布特点,揭示了前翼对后翼绕流流场干扰是引起其俯仰力矩非线性变化的主要原因.计算结果表明:在一定迎角下,该联翼布局飞机前翼绕流发生分离,从而影响后翼绕流流场,引起后翼气动效率下降,导致全机俯仰力矩随飞机迎角发生非线性上扬,对该机飞行性能的提高带来严重影响.

Investigation on non-linear characteristic of pitching moment of joined wing configuration aircraft

The joined wing configuration is one of the best configurations for the next transonic aircraft due to the advantage in the drag and lift characteristic,but the pitching moment changes non-linearly with the attack angle increasing in some condition.To solve the problem,the investigations of flow mechanism over jointed wing configuration were conducted by computational flow method and the aerodynamic characteristic for all parts were also analyzed to combined with the flows interaction between the fore-wing and after-wing and the section aerodynamic force distribution in the wing,under the condition of Ma=0.75.The results show that the lack of aerodynamic efficiency of after-wing is caused by the influence of the separation flow over the fore-wing and the pitching moment of the aircraft will increase nonlinearly with the attack angle.