前置定子导管桨非定常干扰力的理论分析与数值模拟

Theoretical analysis and numerical simulation of unsteady interaction forces on ducted propeller with pre-swirl stators

文章首先对前置定子导管桨非定常干扰力进行了理论分析,给出了桨叶、定子及导管非定常干扰力脉动频率的计算公式。然后,采用RANS方法对带前置定子导管桨的非定常干扰力进行了数值模拟。理论分析表明:带定子导管桨水动力(矩)的脉动频率以转子叶频为基频,轴向力(矩)与横(垂)向力(矩)的脉动频率不会同时出现;轴向力(矩)的脉动频率一般较高,横(垂)向力(矩)可能存在相当低的脉动频率。CFD模拟结果表明:水动力脉动频率与理论值一致;轴向力最大脉动幅值并不在最低脉动频率处;转子横向力脉动主要由低频贡献,而定子及导管的横向力脉动则包含了较丰富的频率成分。

The frequency characteristic of unsteady forces arising from the hydrodynamic interaction between rotors and stators for a ducted propeller with pre-swirl stators is analyzed theoretically. The formula is derived to calculate the frequency of unsteady forces. Furthermore the RANS method is applied to predict the unsteady interaction forces. Theoretical analysis shows that, for a ducted propeller with stators, all the hydrodynamic forces and moments fluctuate at multiples of the rotor＇s blade frequency. The frequencies of axial force and moment differ from those of lateral and vertical forces and moments. Usually the axial components are of high frequency, while the others may be of pretty low frequency. The CFD results for a preswirl stator configuration indicate that the simulated fluctuation frequencies agree well with theoretical values. The largest amplitude of axial force fluctuation does not occur at the lowest frequency. The fluctuations in lateral force consist of the contributions from the rotor at low frequency, and from the stator and duct at quite a range of frequencies.