为便于开展三维模拟研究，将气枪震源的水下激发过程简化为水中高压气泡的脉动，用ANSYS AUTODYN程序建立了水中高压气泡的三维计算模型，并针对不同的深度和边界条件开展了数值模拟。结果表明，高压气泡会产生水中冲击波和后续的气泡脉动压力波；随着气泡所处深度的增加，气泡的脉动频率越来越大，脉动压力波的幅值越来越大，压力增大的幅度越来越小；足够大的有限水域中的刚性边界会导致气泡脉动频率增加，脉动压力增大；接近水底时，气泡脉动频率减小，脉动压力减小。该三维模拟方法可行，能用于平面和立体气枪阵列等复杂的组合模拟，具有优化震源的效果。

In order to facilitate the 3D simulation research，the underwater excitation process of the air-gun seismic source is simplified to the pulsation of the high pressure water bubbles. A 3D digital model of high-pressure air bubble in water was constructed with ANSYS AUTODYN software to study the pulse effect of the air bubble，and the calculation was conducted under different height and boundary conditions. From the results we know that high-pressure air bubble can induce shock wave and bubble pulse pressure wave，and the bubble pulse frequency and the pressure peak both become bigger with the depth increase of the air bubble，but the pressure increase rate becomes smaller. The rigid boundary condition of finite water area with large enough size can increase the bubble pulse frequency and the pulse pressure. In particular，the bubble pulse frequency and pressure will be decreased if the bubble is close to the bottom. The simulation results of this paper show that the 3D simulation method is feasible and can be used for the simulation of the plane and solid complex combinations of air-gun arrays with the effect optimization of the air-gun earthquake source.

云南省陈颙院士工作站专项经费(2014IC007)资助