论文标题
非线性声波通过移动波发射边界激发的非线性声波的显式预测指标方法
Explicit Predictor-Corrector Method for Nonlinear Acoustic Waves Excited by a Moving Wave Emitting Boundary
论文作者
论文摘要
我们提出了一种明确的有限差时间域方法，用于解决一个在一个维度和球形对称性中的移动波发射边界的无损Westervelt方程。该方法基于移动物理域和固定计算域之间的坐标转换。这允许模拟由于介质的本构非线性和由于波发射边界的加速而导致压力波的非线性多普勒调制引起的波轮廓失真的组合效应。在存在冲击和网格运动的情况下，采用了一种预测矫正器方法来增强该方法的数值稳定性。证明该方法可以准确预测非线性波失真的多普勒移位以及由波发射边界的振荡运动引起的振幅调制。提出的方法的新颖性在于它的能力反映了从加速边界发出的有限幅度声波的非线性波轮廓扭曲和冲击衰减速率的多普勒变化。
We present an explicit finite difference time domain method to solve the lossless Westervelt equation for a moving wave emitting boundary in one dimension and in spherical symmetry. The approach is based on a coordinate transformation between a moving physical domain and a fixed computational domain. This allows to simulate the combined effects of wave profile distortion due to the constitutive nonlinearity of the medium and the nonlinear Doppler modulation of a pressure wave due to the acceleration of the wave emitting boundary. A predictor-corrector method is employed to enhance the numerical stability of the method in the presence of shocks and grid motion. It is demonstrated that the method can accurately predict the Doppler shift of nonlinear wave distortion and the amplitude modulation caused by an oscillating motion of the wave emitting boundary. The novelty of the presented methodology lies in its capability to reflect the Doppler shift of the rate of nonlinear wave profile distortion and shock attenuation for finite amplitude acoustic waves emitted from an accelerating boundary.
