A client-server system for simulating and visualizing the random packing of polydiverse spheres

The random packing of particles is important to understand the properties of geological materials, especially unconsolidated sediments that are typically difficult to sample without destroying their structure. Computer simulation algorithms are now widely used to simulate the packing of granular materials but are computationally intensive- typically O(n³) - exercises that are especially complicated when simulating the packing of materials with different size and density distributions. The objective of this project was to develop a polydisperse packing algorithm for scalable execution on multiple processor (i.e., parallel) computers. We present VirtualSoil, a client-server numerical computation package written in C++ that utilizes a portable OpenGL-based graphical user interface and particle visualization system for the client and the message passing interface (MPI library) based parallel computation for the server. The packing algorithm is based on a Monte Carlo simulation in which all the grains simultaneously settle in a concentrated suspension. Input data requirements include the particle size intervals and number of particles in each interval whereas the data output is a final spatial distribution of a packed bed.