螺旋桨尾流-自由叶轮耦合作用的数值模拟

Numerical simulation of coupling effect between wake of propeller and free wheel

为了探讨螺旋桨尾流与自由叶轮的耦合作用,使用SST(剪应力输运)湍流模型对螺旋桨-自由叶轮流场进行数值模拟.使用切割体网格划分方式对流场域进行网格划分,使用滑移网格方法实现螺旋桨和自由叶轮的运动.分析了自由叶轮对螺旋桨尾涡的切割作用,对自由叶轮桨叶上受到的脉动压力和应力分布进行分析.数值模拟的结果表明:自由叶轮桨叶表面上的压力具有明显的周期性,这一周期性和螺旋桨推力脉动的周期性相一致;在近导边处,叶背上脉动压力的幅值大于叶面上,而在其他位置,叶面上的脉动压力幅值大于叶背上,叶背上的脉动压力的幅值由导边向随边减少;在不考虑重力的情况下,自由叶轮上的应力分布与自由叶轮表面压力分布一致,而在考虑重力的情况下,应力分布发生改变且应力值增大.

In order to investigate the coupling effect between the wake of propeller and free wheel,the flow field of propeller and free wheel was studied by using the method of SST(shear stress transport).The flow field was meshed using the Trimer grids,and the sliding mesh method was used to realize the movement of the propeller and the free wheel.The cutting action of the free wheel on the propeller wake vortex was analyzed.The pressure fluctuation on the blade of free wheel was discussed,and the stress distribution on the free wheel was studied.The numerical simulation results show that the pressure on the surface of the free wheel has an obvious periodicity,which is consistent with the periodicity of the propeller thrust pulsation.At the leading edge,the amplitude of the pulsating pressure on the back of blade is larger than that on the face.However,at other area of the blade,the amplitude of the pulsating pressure on the face is larger than that on the back.The amplitude of the pulsating pressure on the leaf back is reduced from the leading edge to the trailing edge.Without considering gravity,the stress distribution on the free wheel is consistent with the pressure distribution.However,in the case of considering gravity,the stress distribution changes and the stress value increases.