Data for "Mid-air Collisions Control the Wavelength of Aeolian Sand Ripples"

The results of the numerical simulations mentioned in the paper. 

The package "ripple formation" contains the bed surface data of the ripple formation simulations. These cases are simulated in a 1m x 0.01m x 0.3m cuboid domain. The initial bed is a flat granular surface of 0.02m in thickness. The density of the fluid rho_f=1.263 kg/m^3; the density of particles rho_p=2650 kg/m^3; the particle diameter d=2.5e-4 m; the kinetic viscosity of the fluid nu=1.49e-5 (m^2)/s. All the settings are based on the wind-blowing sand situation of earth environment. Different wind velocities are tested. "u3, u35, u4, u45..." represent the wind velocity u*=0.3, u*=0.35, u*=0.4, u*=0.45, etc.

Variables in the surface.plt file:

PX: location in the fluid direction. PY: location in the transverse direction. PZ: bed surface elevation at (PX, PY). DP: not used in this paper.

The packages with prefix "preripple-" contain the particle information derived from the pre-rippled simulations. All the settings of them are similar to those in the ripple formation simulations. The right part of the package name declares the changed setting. For example, package "preripple-d200" contains the cases run with a particle diameter d=200 µm (or 2e-4 m), "preripple-rho_f05" contains the cases run with a fluid density rho_f=0.5 kg/m^3. For each run, the wave number of the pre-rippled surface varies every 20 seconds from k=50 to k=500.

Variables in the particle_loc.plt file:

XP, YP, ZP: particle location. DP: particle diameter. UP, VP, WP: particle velocity. FK: particle flight distance. FZ: particle height from the bed surface. FH: maximum particle height from the bed surface. FG: mid-air colliding counter. FT: particle flight duration time.