提出了一种直接测量水的体粘滞系数的实验方法--布里渊散射方法.通过分析剪切粘滞系数和体粘滞系数与布里渊散射线宽的关系,得到了布里渊散射线宽和频移与水的体粘滞系数关系的公式,建立了实验测量水的体粘滞系数的基础,给出了不同温度下水的体粘滞系数的实验测量结果,估算了这种方法的测量误差.实验和理论分析都表明这是一种直接测量水的体粘滞系数的快速而精确的方法.

A method of using Brillouin scattering technique for measuring directly the bulk viscosity of water is proposed. By analyzing the relationship between the line width of Brillouin scattering and the shear and bulk viscosities, a relation of the bulk viscosity of water with the line width and frequency shift of Brillouin scattering is suggested, which is the basis for determining bulk viscosity experimentally. The experimental data of bulk viscosity of water at different temperatures were given. The testing error of this method is analyzed. Both of theory and experiments show that Brillouin scattering technique is a quick and accurate method for measuring bulk viscosity of water.