Measurement of damping constant of liquid surface wave at low frequency by light diffraction method

In order to measure the damping constant of the liquid surface acoustic waves at low-frequency,steady and visible diffraction patterns were obtained by means of diffraction method and it was found that the variation of intensity distribution was related with the position of light spot.After analyzing the relationship between the intensity distribution of the diffraction rings and the liquid surface wave amplitude,the damping constant was obtained.The experimental data are in good agreement with classic hydrodynamics theory,which proves that the diffraction method is applicable for measurement of liquid parameters.