Ultrafast-laser-absorption spectroscopy in the mid-infrared for single-shot, calibration-free temperature and species measurements in low- and high-pressure combustion gases

Abstract

This manuscript presents an ultrafast-laser-absorption-spectroscopy (ULAS) diagnostic capable of providing calibration-free, single-shot measurements of temperature and CO at 5 kHz in combustion gases at low and high pressures. A detailed description of the spectral-fitting routine, data-processing procedures, determination of the instrument response function, and practical considerations for imaging ultrashort pulses in the mid-infrared are presented. The accuracy of the diagnostic was validated at 1000 K and pressures up to 40 bar in a heated-gas cell before being applied to characterize the spatiotemporal evolution of temperature and CO in AP-HTPB and AP-HTPB-aluminum propellant flames at pressures between 1 and 40 bar. The results presented here demonstrate that ULAS in the mid-IR can provide high-fidelity, calibration-free measurements of gas properties with sub-nanosecond time resolution in harsh, high-pressure combustion environments representative of rocket motors.

16 pages, 8 figures

References in corpus (4)

• SpectraPlot.com: Integrated Spectroscopic Modeling of Atomic and Molecular Gases
• Broadband Dual Frequency Comb Spectroscopy in a Rapid Compression Machine
• Cepstral Analysis for Baseline-Insensitive Absorption Spectroscopy Using Light Sources with Pronounced Intensity Variations
• Ultrafast-laser-absorption spectroscopy for single-shot, mid-infrared measurements of temperature, CO, and CH${}_4$ in flames

Cited by in corpus (2)

• Data availability and requirements relevant for the Ariel space mission and other exoplanet atmosphere applications
• The ro-vibrational ${\nu }_2$ mode spectrum of methane investigated by ultrabroadband coherent Raman spectroscopy