Effect of humidity on LIBS measurement of premixed methane–air equivalence ratio

IF 3.8 2区化学 Q1 SPECTROSCOPY

Spectrochimica Acta Part B: Atomic Spectroscopy Pub Date : 2025-09-09 DOI:10.1016/j.sab.2025.107322

Michaela R. Hemming, Kunning G. Xu

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Abstract

The scope of this work is to quantify the impact of ambient air conditions on the laser-induced breakdown spectroscopy (LIBS) analysis of injector flow of premixed methane and air. The tracked species in the LIBS spectra are the Balmer series hydrogen-alpha emitting light at a wavelength of 656.3 nm and an oxygen triplet emitting at 777.4 nm. The ratio of

H_{α} / O

is used to determine not only the equivalence ratio of the premixed propellants but also the concentration of water in stagnant air. The experimental results of the humidity are validated through Boltzmann intensity ratio relationships and simulated spectra using PrismSPECT and used to correct the gas-flow species concentrations. The results show that, for every 10% increase in relative humidity, the corrected

H_{α} / O

ratio will decrease by approximately 6%.

Abstract Image

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湿度对预混合甲烷-空气当量比LIBS测量的影响

这项工作的范围是量化环境空气条件对激光诱导击穿光谱（LIBS）分析预混合甲烷和空气注入流量的影响。LIBS光谱中追踪到的物质是波长为656.3 nm的Balmer系列氢α光和波长为777.4 nm的氧三重态光。Hα/O的比值不仅可以用来确定推进剂预混的当量比，还可以用来确定停滞空气中水的浓度。通过Boltzmann强度比关系和PrismSPECT模拟光谱验证了湿度的实验结果，并用于校正气流物质浓度。结果表明，相对湿度每增加10%，修正后的Hα/O比将下降约6%。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Spectrochimica Acta Part B: Atomic Spectroscopy 物理-光谱学

CiteScore

6.10

自引率

12.10%

发文量

173

审稿时长

81 days

期刊介绍： Spectrochimica Acta Part B: Atomic Spectroscopy, is intended for the rapid publication of both original work and reviews in the following fields: Atomic Emission (AES), Atomic Absorption (AAS) and Atomic Fluorescence (AFS) spectroscopy; Mass Spectrometry (MS) for inorganic analysis covering Spark Source (SS-MS), Inductively Coupled Plasma (ICP-MS), Glow Discharge (GD-MS), and Secondary Ion Mass Spectrometry (SIMS). Laser induced atomic spectroscopy for inorganic analysis, including non-linear optical laser spectroscopy, covering Laser Enhanced Ionization (LEI), Laser Induced Fluorescence (LIF), Resonance Ionization Spectroscopy (RIS) and Resonance Ionization Mass Spectrometry (RIMS); Laser Induced Breakdown Spectroscopy (LIBS); Cavity Ringdown Spectroscopy (CRDS), Laser Ablation Inductively Coupled Plasma Atomic Emission Spectroscopy (LA-ICP-AES) and Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS). X-ray spectrometry, X-ray Optics and Microanalysis, including X-ray fluorescence spectrometry (XRF) and related techniques, in particular Total-reflection X-ray Fluorescence Spectrometry (TXRF), and Synchrotron Radiation-excited Total reflection XRF (SR-TXRF). Manuscripts dealing with (i) fundamentals, (ii) methodology development, (iii)instrumentation, and (iv) applications, can be submitted for publication.