Resumen
Granular is a form of material that is widely used in the industry. To move the granular material, energy is needed to form a flow of granular. Granular instability can be utilized to move granular material. Prevention of jamming and clogging is done by breaking down the parts of the granular, which are locking. Impinging fluid in the granular is used to create granular instability. An observation was made using the experimental method. The granular in the Hele-Shaw cell is shot with fluid in the granular body and results in instability motion. Fluid impinging breaks granular bonds and forms fluid cavities. Furthermore, the fluid cavity moves upward due to unstable conditions. Granular with a strong bond is loose in the form of the agglomerate. Agglomerate is destroyed in the process of moving because there is a drag force. Granular with weak bonds tries to maintain individually form fingering. Granular moves down in the settling process to find a stable position. Instability is affected by the bonds between the grains. A comparison between the cohesion force and the mass weight of the particles is expressed as a granular Bond number Bog. In glass sand material, strong granular bonds occur at granular sizes below 100 µm. Granular bonds affect the movement of instability in groups. The value of the granular Bond number is greater than 1. At sizes of 100 to 230 µm, the granular bond still affects the granular instability with the fingering pattern in the granular motion. The value of the granular Bond number is close to 1. Granular sizes above 230 µm indicate the presence of non-dominant bonds between the grains. The individual granular mass is higher than the cohesion force that occurs at the interface between the granular, and the granular Bond number value is less than 1.