高液压水体中近壁面空化气泡坍塌的动力学特性研究

Dynamic characterization of a singlenear-wall cavitation bubble collapses in a high-hydraulic water body

基于6方程多相流模拟理论并结合Keller-Miksis方程半解析解进行对比验证,建立了适用于研究高液压水体中近壁面空化气泡坍塌问题的数值模型。选取周围水体p_(∞)=10^(6) Pa、p_(∞)=10^(7) Pa、p_(∞)=10^(8) Pa三种高液压工况以及S=0.1R_(0)、S=0.4R_(0)、S=0.7R_(0)、S=1.1R_(0)四种空化气泡与壁面之间间距工况对高液压水体中近壁面空化气泡坍塌的动力学特性进行系统探究。结合数值纹影、压力场无量纲化等后处理技术,对不同组合工况下空化气泡坍塌演变、压力波生成与传播以及壁面径向原点位置压力峰值进行了详细地对比分析,并深入揭示了周围水体液压以及气泡与壁面之间间距对于近壁面空化气泡坍塌动力学特性的影响规律和内在机理。

Combining 6-equation multiphase flow simulation theory with semi-analytic solution of Keller-Miksis equation to realize comparative validation,a numerical model which was used to study the near-wall cavitation bubble collapse problem in a high-hydraulic pressure water body was established.Three high-hydraulic pressure conditions,p_(∞)=10^(6) Pa,p_(∞)=10^(7) Pa and p_(∞)=10^(8) Pa,and four cavitation bubble-wall spacing conditions,S=0.1R_(0),S=0.4R_(0),S=0.7R_(0) and S=1.1R_(0),were selected to systematically investigate the dynamic characteristics of a single near-wall cavitation bubble collapses in a high-hydraulic pressure water body.Combined with the post-processing techniques,such as numerical schlieren and pressure field nondimensionalization,the collapse evolution of the cavitation bubble,the generation and propagation of the pressure waves,and the pressure peak at the radial origin of the wall under different working conditions were compared and analyzed in detail.The influence of the hydraulic pressure of the surrounding water and the spacing between the cavitation bubble and the wall on the collapse dynamics of the near-wall cavitation bubble was elaborated,and the internal mechanism contained was also revealed.