海洋异物接近对导管螺旋桨服役性能影响研究

螺旋桨是目前船舶及海洋装备重要推进装置，其工作可靠性及服役性能对我国海洋战略的实施具有非常重要的意义。复杂海洋环境下螺旋桨服役性能除受到风、浪、流等环境因素影响外，还受到周围其他海洋异物的影响，进而引起螺旋桨载荷特性发生突变。本文基于计算流体力学基础理论，建立导管螺旋桨水动力学数值仿真模型。将海洋异物接近过程简化为准定常过程，分析不同接近距离对导管桨水动力性能的影响。基于流固耦合理论，将水动力学载荷施加在桨叶表面，获得不同接近距离时桨叶应力、应变的变化特性。研究结果表明：海洋异物的接近会对导管桨水动力学特性产生较大的影响作用。当异物接近距离为0.01 m时，导管桨推力将增加11.74%，扭矩增加12.73%，桨叶最大应力值增加32.06%，最大形变量增加30.28%。本文研究工作对导管桨服役性能评估及疲劳寿命预测具有非常重要的参考意义。

Research on the influence of the service performances of the duct propeller in the approaching process of the undersea object

At present, the propeller is the most important propulsion system of ship and marine equipment. Its working reliability and service performance has the important influence on the implementation of our marine strategy. The service performance of propeller has been influenced by some undersea objects such as marine rubbish, large-scale marine fish and so on, in addition to the surrounding marine circumstances (wind, wave and current), which caused the change of propeller's load characteristics. In this article, the hydrodynamics simulation model of duct propeller was established, based on the basic theory of computational fluid mechanics (CFD). The unsteady process of the objects' moving near to the propeller wassim-plified as a quasi-steady process, then the variation of hydrodynamic performance of propeller was analyzed at differentdis-tances between the blade and undersea objects. Based on the fluid-structure interaction (FSI) theory, the hydrodynamicpres-sure distributions were applied into the propeller FEM model, the stress distribution and deformation characteristics during the approaching process were obtained. The results show that when the approach distance reduced to 0.01 m, the thrust of the duct propeller has increased 11.74%, the torque has increased 12.73%, the maximum stress has increased 32.06% and the maximum deformation has increased 30.28%. The research in this article has the important significance in serviceperform-ance evaluation and fatigue life prediction of duct propeller.