基于统计方法的NOPD耗能机理定量分析

Quantitative analysis on energy dissipation mechanism of non-obstructive particle damping technology

非阻塞性微颗粒阻尼(NOPD)是在传统颗粒阻尼和冲击阻尼技术基础上发展起来的新型阻尼技术。本文从湍流物理模型出发,基于统计方法定量分析NOPD技术的耗能机理。经分析认为,高频振动中的NOPD颗粒群其运动状态和湍流运动相似,故引入Kolmogorov的局部各向同性假设,得到NOPD的结构函数表达式及能谱密度表达式。研究结果表明,同种材料,相同颗粒直径情况下,能量耗散率随颗粒群体积比的增加而增大;相同颗粒群体积对比时,能量耗散率随颗粒直径的增加而增大。统计方法的引入,为NOPD的工程应用提供一种有效的定量分析方法。

The non-obstructive particle damping（NOPD） technology has been recently developed on the basis of particle damping and impact damping technologies.A quantitative analysis on the dissipation mechanism of NOPD based on statistical theory was presented.Under high-frequency vibrations,the dense granular motion of NOPD is very similar to turbulence.Thus,Kolmogorov＇s hypothesis in turbulence was adopted to describe the energy spectral density and velocity correlation function of the particles in the NOPD technology.It is shown that the NOPD＇s mean energy dissipation（per unit mass） increases with the increase of either granular diameter or volume ratio of dense granular flow.The quantitative model for the NOPD technology presented in the paper should be useful in possible engineering applications for vibration reduction.