Numerical estimation of cavitation intensity

27th IAHR Symposium on Hydraulic Machinery and Systems

Krumenacker, L.^1 ; Fortes-Patella, R.^1 ; Archer, A.^2

University Grenoble Alpes, LEGI, Grenoble

F-38000, France^1

EDF R and D, Département MFEE, 6 quai Watier, Chatou-Cedex

78401, France^2

关键词: Cavitation intensity;    Flow charac-teristics;    Homogeneous models;    Macroscopic scale;    Material erosion;    Numerical estimation;    Orifice geometries;    Performance loss;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/22/5/052014/pdf
DOI  :  10.1088/1755-1315/22/5/052014

来源: IOP

【 摘 要 】

Cavitation may appear in turbomachinery and in hydraulic orifices, venturis or valves, leading to performance losses, vibrations and material erosion. This study propose a new method to predict the cavitation intensity of the flow, based on a post-processing of unsteady CFD calculations. The paper presents the analyses of cavitating structures' evolution at two different scales: • A macroscopic one in which the growth of cavitating structures is calculated using an URANS software based on a homogeneous model. Simulations of cavitating flows are computed using a barotropic law considering presence of air and interfacial tension, and Reboud's correction on the turbulence model. • Then a small one where a Rayleigh-Plesset software calculates the acoustic energy generated by the implosion of the vapor/gas bubbles with input parameters from macroscopic scale. The volume damage rate of the material during incubation time is supposed to be a part of the cumulated acoustic energy received by the solid wall. The proposed analysis method is applied to calculations on hydrofoil and orifice geometries. Comparisons between model results and experimental works concerning flow characteristic (size of cavity, pressure,velocity) as well as pitting (erosion area, relative cavitation intensity) are presented.