低速大推力导管桨水动力性能预报及优化设计

为研究低速大推力导管桨水动力性能,应用商业软件Fluent,采用RANS方法结合k-ω湍流模型,开展了对原型和改型导管桨敞水状态下的数值计算。采用多运动参考坐标框架(MRF)技术,通过局部网格加密,来模拟桨叶和导管间的间隙流动。重点考察了设计工况点的水动力性能,压力分布等,通过计算分析,对导管桨(包括桨叶、导管以及前后定子)进行了优化设计。研究发现,导管桨在低速高负荷状态下,桨叶吸力面叶梢附近有很大的低压区。提高导管推力占比,可较大幅度提升推进效率。优化后置定子,能使效率得到一定提升。相关结果进行了试验验证,吻合良好,表明该数值研究方法可靠,具有广阔的工程应用前景。

Hydrodynamic Performance Prediction and Optimization Design of Ducted Propeller with Large Thrust under Low Speed

The hydrodynamic performance of a ducted propeller with large thrust under low speed has been numerically simulated by using the commercial software FLUENT.The numerical calculations are carried out for the ducted propeller with the original and modified geometry under the open-water condition by adopting the RANS method with the k-ωturbulence model.The gap flow between the propeller blades and the duct is simulated by the multiple reference frame(MRF)technology with the local refined grids.It mainly focuses on the calculation and analysis of the hydrodynamic performances and the pressure distribution at the design condition for the optimization design of the ducted propeller,including the propeller blades,the duct and the front and rear stator.The results show that there is a large low-pressure region near the tip of the suction surface of the ducted propeller under the condition of low speed and high load.It is also found that the propulsion efficiency can be greatly improved by increasing the thrust ratio of the duct,and can also be improved by optimizing the rear stator.The relevant results agree well with the experimental results,which show that the numerical method is reliable and has broad engineering application prospe with the valid experimental results.