Abstract The objective of this work is to investigate the transient flow around a pre-swirl stator pump-jet propulsor. Based on the discussion of the unsteady analysis, we conduct a comparative study on the wake vortices generated by the hybrid RANS/LES family at the design operating condition J = 1 . 0 . Due to the interaction between the rotor and stator, the rotor working behind the stator causes the fluctuant thrust. However, due to the oncoming flow of the rotor is improved by the pre-swirl effect of the stator, the thrust and pressure fluctuations on the blade surface are low-intensity. Though the shrunk effect of the duct has significantly restricted the tip vortices development, there also exits typical vortices in the wake. The tip vortices induce the shear layer of the duct and then form the second vortices merging into the tip vortices generated by the next blade. The hybrid RANS/LES category catches enough and rich turbulence structures. As they show improved abilities in resolving the vortices in the rotor wake where it is vital for the duct, there are apparent differences in PJP hydrodynamic performance. The IDDES, SDES, and SBES show the prominent resolving ability in vortices motion and evolution than the SAS and DDES.

中文翻译：

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预涡流定子泵喷推进器的瞬态预测与尾涡混合 RANS/LES 模拟的比较研究

摘要 这项工作的目的是研究预涡流定子泵喷推进器周围的瞬态流。基于对非定常分析的讨论，我们对设计工况 J = 1 下混合 RANS/LES 系列产生的尾涡进行了比较研究。0 . 由于转子和定子之间的相互作用，在定子后面工作的转子会产生波动的推力。但是，由于转子的迎面气流通过定子的预涡流作用得到改善，叶片表面的推力和压力波动是低强度的。虽然管道的收缩效应显着限制了尖端涡的发展，但尾流中也存在典型的涡。叶尖涡引起管道的剪切层，然后形成第二个涡流，并与下一个叶片产生的叶尖涡流合并。混合 RANS/LES 类别捕捉到足够丰富的湍流结构。由于它们在解决对管道至关重要的转子尾流中的涡流方面表现出改进的能力，因此 PJP 的流体动力学性能存在明显差异。IDDES、SDES和SBES在涡旋运动和演化方面表现出比SAS和DDES突出的分辨能力。