A Novel Fast Numerical Algorithm for Computing the Dynamics of the Bubble in the Electric-Fluid Field

Gas bubbles may appear in the oil commonly used for dielectric insulation. By the coupled effect of electric and fluid fields, the motion of the bubble will show a complex kinetic behavior. The bubble is very easy to cause partial discharge in the oil. Therefore, it is crucial to study the degree of electric field distortion and the dynamic properties of the bubble under the two coupled fields. In this article, a coupled extended finite element method-finite volume method (XFEM-FVM) algorithm is proposed. Extended finite element method (XFEM) is used for the electric field, and finite volume method (FVM) is used for the fluid field calculation. The coupled electric-fluid field is established by the level-set function. The level-set function is an output of data from the fluid field for the position of the bubble and at the same time an input of data for the description of the interpolation function when calculating the electric field by XFEM. The electric field forces will act as source terms in the fluid control equations. The algorithm eliminates the need to redissect the elements at each time step and thus can reduce the computation time while maintaining accuracy.