桨后自由叶轮理论设计方法研究

为对桨后自由叶轮进行综合设计研究,在前桨给定的前提下,采用螺旋桨的旋涡理论对桨后自由叶轮进行设计。前桨和自由叶轮之间的相互影响通过诱导速度来考虑,诱导速度通过以速度势为基础、采用源汇混合分布以及双曲面元的低阶面元法求得并进行周向平均,将非定常问题转化为定常问题。在实际设计过程中,通过面元法对前桨尾流场进行分析来求其收缩率,从而确定自由叶轮涡轮段直径,并用面元法分别对前桨和自由叶轮进行水动力性能预报,循环迭代直至桨后自由叶轮系统水动力性能收敛。实例设计分析表明:在较低进速条件下,设计的自由叶轮可获得较高的效益,效率最高可提升14.42%。

Theoretical design method investigation of vane wheel after propeller

In order to have comprehensive design and investigation of the vane wheel after propeller, the propeller vortex theory is adopted to design the vane wheel with the forward propeller is given. The inter-action between the forward propeller and the vane wheel is considered through the induced velocities. The induced velocities are obtained through the potential based low order surface panel method employing the hyperboloidal quadrilateral panels and are circumferentially averaged. Therefore, the unsteady problem is translated to steady state. For the purpose to determine the diameter of the turbine section of vane wheel, the wake flow field of the forward propeller is analyzed through the surface panel method. The surface panel method is used to predict the hydrodynamic performance of the system. An iterative calculation method is used until the hydrodynamic performance of the system converges. The analysis of an instance shows that at lower advance speed, the vane wheel after propeller designed through this method can get greater yield and the increase of efficiency can be up to 14.42%.