HardSphereDynamics.jl

Julia package to simulate the dynamics of hard sphere fluids in any number of dimensions via an event-driven algorithm.

Usage

using HardSphereDynamics

d = 3
n = 100   # number of spheres
r = 0.05  # radius

δt = 0.01
final_time = 10

fluid = HardSphereFluid(d, n, r)  # create hard spheres in unit box in d dimensions

num_collisions = 100
pos, vel, times, types = evolve!(fluid, num_collisions)  # return data at each collision

pos, vel, times = evolve!(fluid, δt, final_time)  # return data at given times

Each version of evolve! returns a Vector of positions and a Vector of velocities of each sphere at the given collisions or times. The collision version also returns a vector of collision types.

There are examples of visualizing the results using Makie.jl in 2D and 3D in the examples directory (but no dependency on Makie.jl is assumed).

The spheres may have different radii and masses. Currently they must live in a hard rectangular box, by default a unit cube, but this is relatively easy to improve.

Author

• David P. Sanders, Departamento de Física, Facultad de Ciencias, Universidad Nacional Autónoma de México (UNAM) & Visiting researcher, MIT

Acknowledgements

Financial support is acknowledged from DGAPA-UNAM PAPIIT grant IN-117117 and a Cátedra Marcos Moshinsky (2018).

The author thanks Simon Danisch for help with visualizations using Makie.jl.