论文标题
简单流体中声波传播的分子动力学模拟
Molecular Dynamics Simulation of Soundwave Propagation in a Simple Fluid
论文作者
论文摘要
进行了分子动力学（MD）模拟，以研究流体中声波的传播。声波是由正弦振荡的壁产生的，并由对面壁附近的本地应用的Langevin恒温器an灭。随着波幅度的增加，波形从正弦变为锯齿。对于低频声音，仿真结果与汉堡方程式没有任何拟合参数显示出非常好的一致性。相反，对于高频声音，由于声流而获得了显着的偏差。声音速度可以从波形的傅立叶变换中直接确定，高精度。尽管由于波幅度的非线性效应，很难直接从模拟结果获得衰减率，但可以通过汉堡方程来估计。结果表明，MD模拟是对声波定量分析的有用工具。
A molecular dynamics (MD) simulation was performed to study the propagation of soundwaves in a fluid. Soundwaves are generated by a sinusoidally oscillating wall and annihilated by a locally applied Langevin thermostat near the opposite wall. The waveform changes from sinusoidal to sawtooth with increasing wave amplitude. For low-frequency sounds, the simulation results show very good agreement with Burgers equation without any fitting parameters. In contrast, for highfrequency sounds, significant deviations are obtained because of acoustic streaming. The speed of sound can be directly determined from the Fourier transform of a waveform with high accuracy. Although obtaining the attenuation rate directly from the simulation results is difficult because of the nonlinear effects of the wave amplitude, it can be estimated via Burgers equation. The results demonstrate that MD simulations are a useful tool for the quantitative analysis of soundwaves.
