船舶螺旋桨流固耦合稳态求解算法

Computation algorithm of fluid-structure interaction of marine propellers in steady state

为了研究复合材料变形特性对螺旋桨水动力性能的影响,运用计算流体力学(CFD)理论,结合雷诺时均纳维斯托克斯(RANS)方程和3种湍流模型,计算了螺旋桨的敞水性能并将其和试验结果进行了对比,两者吻合较好,验证了流体计算的准确性.推导了变形后的螺旋桨纵倾、侧斜、叶切面螺距以及拱度等几何参数,并将CFD软件计算和有限元求解耦合起来,即首先利用流体计算软件计算桨叶压力载荷,再将流体载荷通过插值技术传递给有限元,计算出螺旋桨的变形,然后再将变形后的桨叶几何输入流体计算软件,反复迭代,直至结果收敛的过程,实现了螺旋桨稳态性能求解的流固耦合算法.该算法可以计算螺旋桨在不同转速和进速下的应力分布和变形,能够求解螺旋桨变形后的压力分布和水动力性能,适用于复合材料螺旋桨的设计.

To explore the influence of the deformation of composite blades on the hydrodynamic performance of a propeller,the propeller＇s openwater performance was calculated based on a RANS equation,and the results of three different turbulence models were compared with experimental data.The predicted results agree well with the experimental data.The deformed geometrical parameters of the propeller blade such as trim,skew angle,rake,and the sectional pitch angle were derived and a coupled computational fluid dynamics（CFD） and finite element method（FEM） solving steady state was presented in this paper.In the coupling process,the fluid pressure on the blade was calculated with the CFD,and then the calculated fluid pressure was transferred to the FEM by the interpolation on the interface between the FEM and CFD.The deformation of the blades and stress distribution were calculated and then the deformed geometry of the propeller was input into the CFD again.The process was repeated until convergence was achieved and equilibrium was found.The stress distribution and deformation of the propeller blade can be calculated at different advance velocities and revolving velocities by the coupling method,and the pressure of the deformed blade as well as the hydrodynamic performance can be also calculated.The coupling approach is suitable for the design of composite propellers.