Image processing using proper orthogonal and dynamic mode decompositions for the study of cavitation developing on a NACA0015 foil

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• 作者：Sebastien Prothin ; Jean-Yves Billard ; Henda Djeridi
• 刊名：Experiments in Fluids
• 出版年：2016
• 出版时间：October 2016
• 年：2016
• 卷：57
• 期：10
• 全文大小：5,559 KB
• 刊物类别：Engineering
• 刊物主题：Engineering Fluid Dynamics
  Fluids
  Industrial Chemistry and Chemical Engineering
  Measurement Science and Instrumentation
  Thermodynamics
  Theoretical and Applied Mechanics
  
• 出版者：Springer Berlin / Heidelberg
• ISSN：1432-1114
• 卷排序：57

文摘

The purpose of the present study is to get a better understanding of the hydrodynamic instabilities of sheet cavities which develop along solid walls. The main objective is to highlight the spatial and temporal behavior of such a cavity when it develops on a NACA0015 foil at high Reynolds number. Experimental results show a quasi-steady, periodic, bifurcation domain, with aperiodic cavity behavior corresponding to σ/2α values of 5.75, 5, 4.3 and 3.58. Robust mathematical methods of signal postprocessing (proper orthogonal decomposition and dynamic mode decomposition) were applied in order to emphasize the spatio-temporal nature of the flow. These new techniques put in evidence the 3D effects due to the reentrant jet instabilities or due to propagating shock wave mechanism at the origin of the shedding process of the cavitation cloud.