Shocks in supersonic sand.
We measure time-averaged velocity, density, and temperature fields for steady granular flow past a wedge. We find the flow to be supersonic with a speed of granular pressure disturbances (sound speed) equal to about 10% of the flow speed, and we observe shocks nearly identical to those in a supersonic gas. Molecular dynamics simulations of Newton's laws yield fields in quantitative agreement with experiment. A numerical solution of Navier-Stokes-like equations agrees with a molecular dynamics simulation for experimental conditions excluding wall friction.
Rericha
Erin C
EC
Center for Nonlinear Dynamics, The University of Texas at Austin, Austin, TX 78712, USA.
Bizon
Chris
C
Shattuck
Mark D
MD
Swinney
Harry L
HL