船用螺旋桨及桨后发电机设计可行性研究

  目的  以概念船舶节能装置为研究对象，  方法  在船用螺旋桨后布置尾流发电机，利用螺旋桨的高速尾流推动发电机叶轮旋转，从而带动发电机组，将尾流能回收转化为电能，降低船舶的总体能耗。将螺旋桨及海流发电机视作组合推进器一体设计，采用涡格法分析桨的水动力性能，采用原创的改进叶素动量方法评估桨后处于高度非均匀流场中的发电机的性能。采用遗传算法设计最佳的海流发电机叶片几何，为某实船提供设计方案，并通过CFD方法验证方案的性能。  结果  经与原桨比较，结果显示：在进速系数不变的情况下，组合推进器的推力可提高约4%，但收到功率略有增加；如果调整转速，则组合推进器在推力略有损失的情况下可降低能耗3.43%。  结论  计算分析证明了该节能装置的可行性，可作为降速航行的替代方法。

A performance study on the energy recovering turbine behind a marine propeller

  Objectives  This paper develops a design method for a new concept energy conservation device.  Methods  An energy recovery turbine is arranged in the slipstream of a marine propeller with the generator driven by the slipstream of the propeller, in such a way that the turbine converts the kinetic energy into electricity so as to reduce the energy consumption of the ship. In this paper, the propeller and aft turbine are holistically designed. The Vortex Lattice Method is applied in the propeller design while an in-house Matlab code based on the Modified Blade Element Momentum Theory (M-BEMT) is used for turbine performance evaluation. The turbine blade is design and optimized by a Genetic Algorithm (GA). An application case study is completed and a combined thruster solution put forward. The efficiency in open water is simulated on the basis of CFD.  Results  At the same advance coefficient, the efficiency of the combined thruster is about 4% higher than that of the original propeller, with a slight increase in absorbed power. By adjusting the rotational speed, the combined thruster has lower power consumption of around 3.43%.  Conclusions  The feasibility of this new concept device is validated by comparison with that of the original propeller.