Algorithms for uniform particle initialization in domains with complex boundaries

TL;DR

This paper compares existing particle packing algorithms and introduces an improved SPH-based method for generating uniform particle distributions in complex boundary domains, enhancing the accuracy of mesh-free fluid simulations.

Contribution

An improved SPH-based particle packing algorithm for uniform distributions in complex geometries, with open-source implementation and demonstrated accuracy in challenging cases.

Findings

The new algorithm produces more uniform particle distributions.

It outperforms existing methods in complex geometries.

Open-source implementation facilitates reproducibility.

Abstract

Accurate mesh-free simulation of fluid flows involving complex boundaries requires that the boundaries be captured accurately in terms of particles. In the context of incompressible/weakly-compressible fluid flow, the SPH method is more accurate when the particle distribution is uniform. Hence, for the time accurate simulation of flow in the presence of complex boundaries, one must have both an accurate boundary discretization as well as a uniform distribution of particles to initialize the simulation. This process of obtaining an initial uniform distribution of particles is called "particle packing". In this paper, various particle packing algorithms present in the literature are implemented and compared. An improved SPH-based algorithm is proposed which produces uniform particle distributions of both the fluid and solid domains in two and three dimensions. Some challenging geometries are constructed to demonstrate the accuracy of the new algorithm. The implementation of the algorithm is open source and the manuscript is fully reproducible.