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通过数值模拟方法研究多段机翼的地面效应,采用有限体积法求解质量加权平均Navier-Stokes方程,湍流模型选用Spalart-Allmaras模型,利用运动壁面边界模拟地面的相对运动。计算结果分析表明:随着飞行高度的降低,多段机翼的升力、阻力和低头力矩均减小;迎角、展弦比越大,地面效应越明显,升力损失越大;升力的减小主要是由于地面效应导致机翼下方静压增大的气流通过缝隙进入机翼上表面流场,使得机翼下翼面压力的增加量小于上翼面吸力的减小量;地面效应使机翼上翼面翼尖容易发生分离;翼尖涡沿着展向方向向外移动,机翼诱导阻力减小。该文研究结果可以为大型飞机的增升装置地面效应设计提供参考依据。
The numerical simulation method is used to study the ground effect of multiple wings. The finite volume method is used to solve the mass weighted average Navier-Stokes equations. The turbulence model is Spalart-Allmaras model, and the moving wall boundary is used to simulate the ground relative motion. The calculation results show that the lift, drag and bow torque of multiple sections of wing decrease with the decrease of flight altitude. The larger the angle of attack and the aspect ratio, the more obvious the ground effect and the greater the lift loss. The decrease of lift is mainly Due to the ground effect, the airflow with increased static pressure under the wing passes through the gap and enters the flow field on the upper surface of the wing so that the pressure increase under the wing is smaller than the decrease of the suction on the upper airfoil. The ground effect causes the wing upper wing Wing tip prone to separation; wing tip vortex moves outward along the direction of expansion, wing induced resistance decreases. The results of this paper can provide a reference for the design of ground effect of lifting devices in large aircraft.