Semi-implicit Lagrangian Voronoi Approximation for the incompressible Navier-Stokes equations

TL;DR

This paper presents SILVA, a new semi-implicit Lagrangian Voronoi approximation method for solving incompressible Euler and Navier-Stokes equations, combining efficiency, robustness, and flexibility in handling complex flow deformations.

Contribution

SILVA introduces a novel meshless, semi-implicit approach using Voronoi tessellations that eliminates remapping, enabling efficient simulation of complex fluid flows with large deformations.

Findings

SILVA effectively simulates viscous, inviscid, and multi-phase flows.

Compared to ISPH, SILVA has a sparser stiffness matrix and easier boundary condition implementation.

SILVA handles large deformations without remapping or reconnection procedures.

Abstract

We introduce Semi-Implicit Lagrangian Voronoi Approximation (SILVA), a novel numerical method for the solution of the incompressible Euler and Navier-Stokes equations, which combines the efficiency of semi-implicit time marching schemes with the robustness of time-dependent Voronoi tessellations. In SILVA, the numerical solution is stored at particles, which move with the fluid velocity and also play the role of the generators of the computational mesh. The Voronoi mesh is rapidly regenerated at each time step, allowing large deformations with topology changes. As opposed to the reconnection-based Arbitrary-Lagrangian-Eulerian schemes, we need no remapping stage. A semi-implicit scheme is devised in the context of moving Voronoi meshes to project the velocity field onto a divergence-free manifold. We validate SILVA by illustrative benchmarks, including viscous, inviscid, and multi-phase flows. Compared to its closest competitor, the Incompressible Smoothed Particle Hydrodynamics (ISPH) method, SILVA offers a sparser stiffness matrix and facilitates the implementation of no-slip and free-slip boundary conditions.