激光热弹激励流-固界面波声场的数值模拟

利用热弹体运动方程和热传导方程耦合问题的变换域解,求解其极点留数的解析表达式.通过数值求根方法,得出铁-水、铝-水、铁-空气、铝-空气这4种流-固界面波的速度值,从而得到4种界面各界波相应的极点留数值.用快速傅立叶变换(FFT)技术得到脉冲激光线源热弹激励时流-固界面波瞬态位移波形.计算结果表明,这2种界面波不但存在于液-固界面,而且存在于气-固界面,但这2种流-固界面上波成分的相对幅度、脉冲持续时间不同.

Numerical Simulation of Fluid-solid Interface Waves Acoustic Field Excited Thermoelastically by Pulsed Laser

For the transformed solution of the thermoelastic and heat conduction equations coupled problem,the analytical representation of the pole residues is obtained.The velocities of the fluid-solid interface waves propagated along the iron-water,aluminium-water,iron-air,aluminium-air interfaces are solved by using the numerical root-finding method,thus the pole residues of the interface waves for the four interfaces are obtained.The transient displacement waveforms excited thermoelastically by a pulsed laser line source are performed numerically.The results show that the two kinds of interface waves exist at the liquid-solid interface and also exist at air-solid interface,but the relative amplitude,the pulse duration for the corresponding wave component at the two kinds of fluid-solid interfaces are different.