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论文类型：期刊论文
发表时间：2019-07-01
发表刊物：EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
收录刊物：SCIE、EI
卷号：76
页面范围：223-232
ISSN号：0997-7546
关键字：Shedding mechanism; Vortex structures; Development stage; Ventilated partial cavitating flows; Numerical modeling
摘要：Ventilated partial cavitation is a complex multi-phase turbulent flow due to the strong interactions between gas and liquid. In the present work, we specially focus on the numerical modeling and simulation of the shedding mechanism and vortex structures. The Reynolds Averaged Navier-Stokes (RANS) method combined with a filter-based turbulence model (FBM) is proposed to explore the physical mechanism of the ventilated partial cavitating flows. Experimental results of cavity evolution and pressure are utilized to assess the prediction ability of the proposed method. Good agreements are observed between experimental measurements and numerical predictions, including the ventilated cavity growth, break off, shedding and the transient dynamic pressure inside the cavity. Based on the model strategy, the cavity dynamic evolution and shedding mechanism are analyzed. The results indicate that the re-entrant flow gives birth to the gas leakage at the cavity interface and is responsible for the ventilated cavity shedding. In addition, streamline vortex is presented to reveal the ventilated cavity shedding characteristics. Moreover, based on the vorticity transport equation, the influence of velocity gradient, fluid volumetric expansion/contraction, pressure gradient and the viscous dissipation factors on the vortex production in ventilated cavitating flows is examined. The present study can provide important basis to better understand the shedding mechanism and vortex structures on the development stage of ventilated partial cavitating flows. (C) 2019 Elsevier Masson SAS. All rights reserved.