Moment-preserving particle merging via non-negative least squares

Georgii Oblapenko; Manuel Torrilhon

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arXiv · 2604.00668

Moment-preserving particle merging via non-negative least squares

Georgii Oblapenko·Manuel Torrilhon

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Abstract

A novel particle merging algorithm for rarefied gas dynamics simulations is proposed that can conserve arbitrary velocity and spatial moments of the particle distribution via solving a non-negative least squares problem. An extension that preserves both exact and approximate collision rates is also derived. The algorithm is applied to the simulation of several model rarefied gas dynamics problems, where it exhibits noticeably lower merging-induced error in key macroscopic quantities.

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Georgii Oblapenko, Manuel Torrilhon. 2026-04-01. Moment-preserving particle merging via non-negative least squares. https://arxiv.org/abs/2604.00668

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