Influence of vibration on granular flowability and its mechanism of aided flow
来源期刊:中南大学学报(英文版)2001年第4期
论文作者:WU Ai-xiang SUN Ye-zhi LI Jian-hua
文章页码:252 - 257
Key words:granular media; vibrating aided flow; body wave; mechanism
Abstract: Regarding flowing granular media as weak transverse isotropic media, the phase velocity expressions of wave P, wave S Handwave SV were deduced, the propagation characteristics ofwaves in flowing granular media were analyzed. The experiments show that vibration has great influence on granular fluidity. The wavefront of wave P is elliptic or closely elliptic, the wavefront of wave SH is elliptic, and the wavefront of wave SV is not elliptic. Wave propagation in the granular flowing field attenuates layer after layer. The theory and experiment both substantiate that the density difference is the key factor which leads to the attenuation of vibrating energy. In terms of characteristics of wave propagation one can deduce that vibrating waves have less influence on flowability of granules when the amplitude and frequency are small. However, when the amplitude and frequency increase gradually, the eccentricity of ellipsoid, the viscosity resistance and inner friction among granules, and shear intensity of granules decrease, and the loosening coefficient of granules increases, which shows the granules have better flowability.