对转式全回转舵桨的立柱优化分析

Strut optimization analysis of azimuth thruster with contra-rotating propellers

[目的]旨在研究立柱对对转式全回转舵桨敞水性能的影响。[方法]采用基于雷诺平均方法与k-ω湍流模型,对不同立柱型式的对转式全回转舵桨进行模型尺度和实尺度下的水动力性能预报,研究流场特性并监测后桨伴流,分析优化前后立柱尾部的流动分离现象。[结果]结果表明,立柱前缘削薄并整体前移的优化方案,使得整个舵桨的敞水推进效率提高1.01%;立柱采用扭曲设计且切面引入拱度的优化方案,使得敞水推进效率提高1.15%。另外,模型尺度的立柱尾部流动分离比实尺度的严重。[结论]研究表明,优化后的立柱可以改善立柱尾部的流动分离现象,提高后桨吸收前桨的尾涡能量,增加后桨流入量,对于提高对转式全回转舵桨的推进性能具有工程实用意义。

[Objective]This paper aims to investigate the effect of the strut geometry on the open water performance of the azimuth thruster with contra-rotating propellers(CRPs).[Methods]The RANS method and k-ωturbulence model are applied to predict the hydrodynamic performance of an azimuth thruster with CRPs and different strut design schemes at model scale and real scale in open water.Meanwhile,the flow field characteristics and wake fraction of the rear propeller are explored,and analysis on the flow separation at the stern of the strut after and before optimization is carried out.[Results]The results show that the optimization scheme of the struts moving forward and the leading edge thinning increases the propeller open water efficiency by 1.01%.The optimization scheme of the struts adopting a twist design and the strut section introducing cambers increases that value by 1.15%.In addition,the flow separation at the model scale is more serious than that at the real scale.[Conclusions]It is found that the optimized struts can reduce the flow separation at the stern,improve the rear propeller absorption of the wake vortex energy of the front propeller and increase the inflow of the rear propeller,which has practical engineering significance for improving the propulsion performance of an azimuth thruster with CRPs.