The drag force experienced by a projectile in granular medium under gravity

Abstract

To describe different behaviors of a projectile into a granular media, a model with both viscous drag and hydrostatic drag has been suggested. Analyses show that the parameter Γ plays a key role in determining the forms of the solutions to this model. When ΓΓ≥2, the viscous drag is dominant. In these two cases, the projectile moves in the granular media with reverse deceleration variances. Experiments have been performed to verify this argument, and the obtained u(t) curves confirm this prediction.

Settling velocity of equiaxed dendrites in a tube

“…The settling velocity changes to a constant when the net gravitational force (gravity minus buoyancy) equals the drag force. [14] This can be written as…”