为研究柔性螺旋桨的气动弹性效应和推进性能,以成熟的计算流体力学和计算固体力学软件为平台,建立径向点插值方法(RPIM)以完成网格节点的位移传递,由虚位移原理辅助完成载荷传递的螺旋桨气动弹性分析框架.该方法可以避免生成奇异的插值矩阵,具有数值稳定性,适用于任意分布的节点,且能保证在数据传递过程中不发生能量损耗.流场网格更新通过Delaunay映射方法实现.研究结果表明:在所设置的工况中,桨叶沿来流方向的最大变形量可达桨叶半径的9.4%,旋转平面内的变形量约为来流方向上的52.1%;变形会使螺旋桨的迎风面受到更大的正压力,进而导致柔性螺旋桨产生比刚性螺旋桨更高的推力和扭矩,其最大改变量分别为7.2%和9.9%;气动弹性效应基本不会对推进效率产生影响.综上,在螺旋桨处于大推力、低速工况下时,气动弹性效应对推进性能有较大的影响,能够在基本维持原有效率不变的情况下提高推力.

To investigate the aeroelasticity effect and propulsion performance of flexible propellers, the mature computational fluid dynamics (CFD) and computational solid dynamics (CSD) softwares are used as the platform to establish an aeroelasticity analysis framework. The radial point interpolation method (RPIM) is applied to achieve the transmission of displacement, while the transfer of aerodynamic loads is assisted by the principle of virtual displacement. This method can avoid generating singular interpolation matrix. Moreover, it has numerical stability, which is suitable for nodes with arbitrary distribution. Furthermore, it can avoid energy loss during data transmission. The update of fluid domain grid is implemented by using the Delaunay mapping method. The results show that the maximum deformation of blade along the incoming flow direction can reach 9.4% of blade radius, and the deformation in the rotation plane is about 52.1% of flow direction. The deformation exerts a greater positive pressure on the windward side of the propeller, which, in turn, results in a higher thrust and torque in flexible propellers than in rigidity propellers. Their maximum changes can reach 7.2% and 9.9%, respectively. The aeroelasticity effect does not substantially affect the propulsion efficiency. Hence, the aeroelasticity effect has a greater impact on the propulsion performance when the propeller is under high thrust and low speed conditions. It can increase the thrust while basically maintaining the original efficiency.