This paper presents a high-order discontinuous Galerkin (DG) scheme for the simulation of wave propagation through coupled elastic-acoustic media. We use a first-order stress-velocity formulation, and derive a simple upwind-like numerical flux which weakly imposes continuity of the normal velocity and traction at elastic-acoustic interfaces. When combined with easily invertible weight-adjusted mass matrices [1], [2], [3], the resulting method is efficient, consistent, and energy stable on curvilinear meshes and for arbitrary heterogeneous media, including anisotropy and sub-cell (micro) heterogeneities. We numerically verify the high order accuracy and stability of the proposed method, and investigate its performance for applications in photoacoustic tomography.

本文提出了一种高阶不连续伽勒金（DG）方案，用于模拟通过耦合弹性声介质传播的波。我们使用一阶应力-速度公式，并得出一个简单的逆风状数值通量，该通量弱地在弹性声界面处施加了法向速度和牵引力的连续性。当与易于可逆的重量调整质量矩阵[1]，[2]，[3]结合使用时，所得方法在曲线网格上以及包括各向异性和子单元（微观）在内的任意异质介质上都是高效，一致且能量稳定的）异质性。我们数值验证了该方法的高阶精度和稳定性，并研究了其在光声层析成像中的应用性能。