地效飞行器波浪环境下气动特性分析

Aerodynamic Characteristics Analysis of Ground Effect Vehicle in Wave Environment

基于计算流体力学与海洋波浪理论,非定常不可压RANS方程采用有限体积法求解,采用VOF液面捕捉法、整体动网格法、速度入口造波法,探究波浪环境以及无动力地效飞行器姿态对其气动性能影响。结果表明,在规则波浪情况下,无动力地效飞行器最佳巡航角度为4°左右,在上行波时,升阻比下降,气动力性能相对减弱;在下行波时,升阻比上升,气动力性能相对增强,2°攻角变化规律相反。对于相同姿态角,波浪位置对地效飞行器机翼的气动性能影响较小,上翼面压力系数变化较小,在上行波时,机翼下表面压力增加,正压区范围扩大;在下行波时则相反。地效飞行器处于同一波浪位置时,上翼面前缘负压区随攻角增大而增大,下翼面前缘正压区随攻角增大而减小,压力系数快速增加。

Based on computational fluid mechanics and ocean wave theory,the unsteady incompressible RANS equation was solved by the Finite Volume Method.The velocity inlet boundary is used to generate numerical wave coupled with the volume of fluid model and the global moving mesh method is applied to investigate the influence of wave environment and attitude on the aerodynamic performance of unpowered WIG vehicle.The results show that:the optimal cruising angle of an unpowered WIG vehicle is about 4o in the regular wave case.In the rising stage of waves,the lift-drag ratio decreases and the aerodynamic performance is relatively weakened.In the wave descent stage,the liftdrag ratio increases and the aerodynamic performance is relatively enhanced,and the change law of 2°angle of attack is opposite to the other cases.At the same angle of attack,different wave positions have little effect on the aerodynamic performance of the wing,and the pressure coefficient of the upper wing is basically unchanged.In the wave descent stage,the pressure on the lower wing decreases and the positive pressure area decreases.At the same wave position,with the increase of the Angle of attack,the negative pressure area at the front edge of the upper wing increases,the positive pressure area of the front edge of the lower wing decreases and the corresponding pressure coefficient increases sharply.