Study of the phase-change coefficients of the cavitation model in cavitation flow fields generated from cone cavitator

WANG Bai-qiu¹, WANG Cong¹, HUANG Hai-long^2,3, ZHANG Jia-zhong¹

1.School of Astronautics, Harbin Institute of Technology, Harbin 150001, China;2.Beijing Institute of Astronautical Systems Engineering, Beijing 100076, China;3.School of Civil Engineering, Harbin Institute of Technology, Harbin 150090, China



Abstract:

The influence of phase-change coefficients variations in the Singhal cavitation model on the calculation results has been numerically studied. By comparing the numerical results and experimental data, the relationship between the coefficients and cavitation numbers is obtained. The calculation results of 2d axisymmetrical cylinder with 45-degree cone cavitator show that under different cavitation numbers, there are three typical kind of cavities, which are respectively main cavity, secondary cavity and rear cavity. The coefficients variations have a great influence respectively on the three type cavities in shape, collapse position, collapse strength, etc, and different cavitation numbers are corresponding to different phase-change coefficients. The cavitation flow field can be divided into three typical zones according to the cavitation number: weak-cavitation zone, secondary-cavitation zone and supercavitation zone. For 45-degree cone cavitator cylinder, the evaporation coefficients will firstly decrease and then increase with the decrease of cavitation numbers in secondary-cavitation zone, while the condensation coefficients keep relatively lower and almost unchanged. In weak-cavitation zone, there only exists the smaller main cavity attached to the model head or there is no obvious cavity. In supercavitation zone, the secondary cavity attached to the model will fall off and merge into the new rear cavity.ª¤

Key words:  Cavitation model  phase-change  evaporation coefficients  condensation coefficients  secondary cavitationª¤

DOI£º10.11916/j.issn.1005-9113.2012.04.001

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