Production of nitric oxide by a fragmenting bolide: An exploratory numerical study

TL;DR

This study uses numerical simulations to explore how small meteoroids and their fragments produce nitric oxide in the upper atmosphere during atmospheric entry, providing insights into shock wave effects and chemical processes.

Contribution

It is the first to numerically model nitric oxide production from small meteoroids using CFD, focusing on fragmenting bodies at high altitudes.

Findings

Good agreement with previous studies on NO production.

Model simulates small meteoroid behavior at 70-80 km altitude.

Provides a basis for understanding meteoric NO in atmospheric chemistry.

Abstract

A meteoroid's hypersonic passage through the Earth's atmosphere results in ablational and fragmentational mass loss. Potential shock waves associated with a parent object as well as its fragments can modify the surrounding atmosphere and produce a range of physico-chemical effects. Some of the thermally driven chemical and physical processes induced by meteoroid-fragment generated shock waves, such as nitric oxide (NO) production, are less understood. Any estimates of meteoric NO production depend not only on a quantifiable meteoroid population and a rate of fragmentation, with a size capable of producing high temperature flows, but also on understanding the physical properties of the meteor flows along with their thermal history. We performed an exploratory pilot numerical study using ANSYS Fluent, the CFD code, to investigate the production of NO in the upper atmosphere by small meteoroids (or fragments of meteoroids after they undergo a disruption episode) in the size range from 1 cm m to 1 m. Our model uses the simulation of a spherical body in the continuum flow at 70 and 80 km altitude to approximate the behaviour of a small meteoroid capable of producing NO. The results presented in this exploratory study are in good agreement with previous studies.