Flow patterns and wall stresses in a two‐dimensional bin with an obstacle

Abstract

This work investigates the combined effects of an obstacle and the position of the exit on flow patterns and wall stresses in a two‐dimensional bin with an obstacle. The obstacles used were (1) an isosceles triangle and (2) a hexahedron. The instantaneous vertical velocity distribution at a particular height from the bottom of the bin was determined from two consecutive flow images. The variations in the dynamic wall stresses with time were measured using a pressure gauge, which simultaneously measured the normal and shear stresses of the granular solids. For a bin with an isosceles triangular obstacle and a centric exit, the particulate solids between the sidewall and the obstacle are accelerated. This effect not only suppresses the formation of a network of the contact forces within these particulate solids, but also promotes the direct impact of the particulate solids on the side‐wall. In contrast, for a bin with an isosceles triangular obstacle and an exit on the right, the obstacle divides the granular bed into a flowing stream and a non‐moving zone of granular material. This effect not only facilitates the formation of a network of the contact forces in the quasi‐stagnant zone adjacent to the left‐side wall, but also shrinks the wall shear region along the right‐side wall.

Key words:

• flat‐bottom bin
• obstacle
• pressure pulsation
• centric
• eccentric

Notes

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