单个三维气泡的动力学特性研究

Dynamics for Single Three-dimensional Bubble

模拟了单个气泡在重力场作用下动态特性,假设流场为无粘、无旋且不可压的理想流体,采用三角形单元离散流场边界,并用边界积分法求解流场,用Mixed-Eulerian-Lagrangian方法模拟气泡的演化,并在必要的时候采用三维光顺方法对气泡表面及其速度势分布进行光顺,使计算程序更准确,更稳定。在分析过程中,将本文三维模型的计算结果与Rayleigh-Plesset气泡模型及试验数据进行对比分析,三维模型的计算值与精确解及实验数据吻合很好,表明本文方法及计算模型具有较高的精度,并通过对比改变不同物理参数时对气泡运动周期及射流速度的影响,得出一些规律性的曲线,旨在为相关的水下气泡动力学分析提供参考。

Dynamics of a single bubble in gravitational field is simulated, and the flow field is assumed to be inviscid, irrotational and incompressible. Triangular elements are adopted to discretize the boundary of flow field, boundary integral method is chosen to solve the flow field and the evolution of bubble is simulated with Mixed-Eulerian-Lagrangian method. Three-dimensional smoothing method is applied to smooth the bubble surface and the velocity potential to make the computing process more accurate and stable. In the analysis, the calculated results of the three-dimensional model are compared with the experimental data of Rayleigh-Plesset bubble model, and it is found that the calculated results coincide well with the exact results and experimental data, which show that the algorithm and 3D model are of high accuracy. By comparing the effects of different physical parameters on the motion cycle of bubble and velocity of jet, several curves for describing the regularity are obtained.