Granular flow induced by high-speed in-plane impact on particle sheet and its fluid dynamic description

The granular flow induced by high-speed impact was experimentally and numerically investigated. A sheet of free-falling small glass beads was formed in the test chamber at low pressure. A spherical projectile or a slender puff of particle cloud launched by the ballistic range collided with the particle sheet in the in-plane direction to obtain a quasi- two-dimensional situation. The observation by the high-speed camera revealed that the shock-layer-like compressed zone and the void zone were formed on the forward side and the backward side, respectively. To describe such phenomena in the framework of the continuum fluid dynamics, the compressible and non-expanding (CNE) fluid model was applied and the two-dimensional Euler equations were numerically solved by the finite volume method with the Riemann solver formulated for the CNE fluid model. Finding an appropriate set of the parameters in the equation of state, qualitatively good agreement was obtained between the experimental and the computational results.