一种对船桨干扰问题的黏势流耦合求解方法

基于黏性流计算流体力学(CFD)及势流理论,建立了一种黏流雷诺平均方程/面元法耦合迭代求解方法,对船桨相互作用问题进行了数值模拟.自由面的船体绕流场模拟应用CFD黏流方法,螺旋桨水动力载荷计算采用势流面元法.在黏性流场模拟中得到桨盘面处的总速度分布,减去螺旋桨诱导速度得到实效伴流速度并作为势流计算速度进口条件,螺旋桨效应以体积力的形式在黏性流场中体现.计算值与试验值的对比结果表明,黏势流耦合迭代求解方法能较好地预报船桨干扰问题,且较全域船桨离散化网格CFD求解船桨干扰的方法,计算量大为减少.该方法充分融合了黏势流方法的优点,既能计及黏性效应又能发挥势流快速准确的优势,能够拓展应用于船体及螺旋桨性能预报及设计优化的研究.

A Method of Viscous CFD/Potential Flow Coupling Iterative Solution for Ship/Propeller Interaction

Abstract： Theory prediction method of ship/propulsion interaction is the technical difficulty for predictions of ship speed performance. A viscous RANS/panel method coupling with the iterative method was proposed to simulate ship/propulsion interaction based on the viscous CFD/potential flow theory. The viscous flow around surface ships was computed by the CFD method and hydrodynamic loads for propellers were computed by the potential panel method. The total velocity in the domain of propeller plane was obtained by viscous solver. The induced propeller velocity was substracted from the total velocity, and the effective velocity was obtained and used as the propeller inflow. The effective wake velocity was renewed to calculate the force and induced velocity by the potential solver. Then the iteratations were recycled. The propeller effects were treated as body force terms. The present results of calculation were compared with the experimental data, which shows that the coupling method can solve the ship/propeller interaction very well, and the computational cost is significantly reduced. The coupling method proposed, which incarnates viscous effect and efficiency of potential flow computation, can be extended to predict ship/propulsion interaction performance and used for design and optimization research.