GRAVITATIONAL OVERTURNING IN STRATIFIED PARTICULATE FLOWS

作者：Sobral Yuri D^*; Hinch E John

来源：SIAM Journal on Applied Mathematics, 2011, 71(6): 2151-2167.

DOI：10.1137/100802426

• gravitational overturning
• fluidized beds
• bubble formation
• secondary instability
• concentration waves

With the motivation of understanding the formation of bubbles in fluidized beds, we investigate the stability of stratified particulate flows to transverse disturbances, leading to gravitational overturning. We consider a one-fluid model in which particles are responsible for the stratification of the flow but do not slip relative to the fluid and do not diffuse. A linear stability analysis and a numerical simulation of the governing equations are performed in order to determine and characterize the instability of the flow. We observe that stratified flows are unstable to transverse disturbances and that the instability is driven by a tilt-and-slide mechanism that creates ascending regions of low concentration of particles and descending regions of high concentration of particles. This mechanism might be related to the formation of bubbles in fluidized beds.

• 出版日期2011