Acoustic Wave Equation Modeling in Cylindrical Coordinates with Convolutional PML

The finite difference modelling of wave equation are generally performed in Cartesian coordinates which is relatively easy to implement, but when dealing 3D axisymmetric media, even for simple layered medium, the simulation can be very time-consuming. Fortunately, for 3D (approximate) axisymmetric model, a more economical approach is to solve the wave equation in cylindrical coordinates, which can reduce the computation time to nearly as short as that of the 2D calculations. In this paper, the unsplit convolutional PML absorbing boundary is first implemented in 3D acoustic wave equation modelling in cylindrical coordinates. Numerical simulation results show that it’s an accurate and efficient algorithm and exhibits good performance for absorbing artificial reflection. Thus our algorithm can be a tantalizing choice to efficiently simulate axisymmetric models.