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arXiv · 2609.25073

Reactive Trace Species Modeling with the Simulation Tool PICLas

Simone Lauterbach·Kim-Sophie Ellenberger·Stefanos Fasoulas·Marcel Pfeiffer
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Abstract

A species-specific weighting scheme for the Natural-Sample-Size collision model within the Direct Simulation Monte Carlo method is developed and implemented in the open-source gas and plasma solver PICLas. The implemented weighting scheme places particular emphasis on chemical reactions and ionization processes of trace species in order to guarantee physically accurate and low-noise simulations of atmospheric entry processes. The successful implementation and the conservation of momentum and energy during relaxation processes and chemical reactions are verified through a reservoir simulation of a reacting air mixture. As a more sophisticated validation case, atmospheric entry simulations of a cylinder at an altitude of 108 km are investigated. In a final step, the developed weighting scheme is employed to investigate ionization processes in the shock layer surrounding the RAM-C II reentry probe during atmospheric entry. The simulations showed very good agreement with experimental flight data and reduced noise in the rarefied regions for the charged species.

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Simone Lauterbach, Kim-Sophie Ellenberger, Stefanos Fasoulas, Marcel Pfeiffer. 2026-09-18. Reactive Trace Species Modeling with the Simulation Tool PICLas. https://arxiv.org/abs/2609.25073

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