An experimental study of fluidization post impinging fluid in granular bed for breaking sedimentation

Abstract

The impinging fluid can be used as a prevention of sedimentation in the flow of the pipe and the mixing process. Sedimentation is a problem that often occurs in fluid transportation and fluidization. Granular material behavior due to impinging is a phenomenon that is rarely studied. This condition is difficult to observe due to the position of complex fluid movements in the bed. The study tries to find the behavior of fluidization at various granular sizes. The effect of impinging into the granular bed has been observed with experimental studies. Hele-Shaw cell is used as equipment for the observation process. The glass sand is used as a medium of fluidization. The high-speed fluid is injected into a granular bed in a short time. Granular material moves because of the pressure impinging as fluidization. The motion of the granular material is observed by a camera to determine the behavior of the granular material. The primary outcome of the present study is the identification of two very distinct regimes. There are two types of post-impinging fluidization. The first type is the fluid cavity and fluidization. The condition starts with a fluid cavity expansion and continues with the fluidization process. The fluid cavity occurs because the fluid shock pressure pushes the granular material upward. Granular bonds hold the particles' connection and form a cavity. Fluidization after cavity expansion is a settling motion that is influenced by gravity, buoyancy, drag, and granular bonds. The other type is a local fluidized state. The limit for the occurrence of fluid cavity and fluidization is observed with the Reynolds number of impinging. The Reynolds number of impinging is calculated by the velocity of entry of the shock fluid in the granular and multiplied size of the particles divided by the viscosity. The fluid cavity post-impinging occurs at the Reynolds number of the impinging process less than 4,000 (laminar and transition flow area). The local fluidized state has Re of impinging more than 4,000, and the fluidization follows the flow and disappears immediately. This condition causes the bonding of the granules cannot maintain the agglomeration of the granules