Experimental investigations of granular temperature in vertical vibrated beds

Granular temperature is a key property in granular flows, however, this topic has not been fully understood due to many research difficulties. The studies about granular temperature in vibrated beds are relatively few. This study presents experimental results to investigate the role of granular temperatures in vertical vibrated beds. The image processing technology and particle tracking method were employed in a series of experiments in vibrated granular beds, dry or with small amount of liquids. We briefly review one of our earlier published experimental works dealing with granular temperature in dry granular beds influenced by vibrational conditions. The granular temperature increases with the increasing vibrational acceleration and vibrational velocity. The other new experimental results of granular temperatures in a wet vibrated bed are also presented and compared with dry systems. The granular temperature decreases with increasing viscosity of the added liquid and increasing liquid amount.

Graphical abstractThe granular temperature decreases with the increasing viscosity β and content of the added liquid V⁎. Adding a more viscous liquid in the granular bed causes the system to become more cohesive, with higher liquid bridge force and viscous force. This effect cools down the random motions of particles. Besides, the energy dissipation in the system also increases. Thus, the granular temperature in the bed decreases.Figure optionsDownload full-size imageDownload as PowerPoint slide