Experiments on Drag Force in Granular Flow Past a Cylinder

Granular flows are observed in natural phenomena such as landslides, and snow avalanches and pose a serious threat to infrastructure and the community living in the hilly areas. Granular avalanches often interact with obstacles such as large electric poles, aerial lifts, cable cars, etc. that leads to significant forces on these structures. A good understanding of the interaction of granular flows with solid structures and the resultant drag force is therefore very important. The present experimental study embarks on studying the interaction of shallow granular flows with cylindrical obstacles with a particular focus on estimating the drag force acting on the cylinder as a granular avalanche impacts it. An inclined chute is fabricated to generate slow and rapid granular flow with the facilities for drag calculation and shock wave visualisation at various chute inclinations. Velocity profiles are estimated using the particle image velocimetry method and the drag force acting on the models is calculated using the load cells with a strain gauge force measurement system. Scaling analysis is performed to extract generalised trends in the drag force.