Mid-infrared laser absorption spectroscopy for carbon oxides in harsh environments

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Advancements in measurement science are presented regarding in situ laser-based detection of CO and CO2 in harsh combustion environments. Mid-infrared absorption sensing strategies, utilizing transitions in the 2.7 and 4.3 micron vibrational bands for CO2 and the 4.8 micron vibrational band for CO, were developed to enable sensitive measurements of temperature and carbon oxide concentrations in high-temperature gases. These new strategies (1) extend the utility of carbon oxide absorption sensing for hostile aeroengine applications and (2) offer significant improvements to previous methods for shock tube kinetics studies. The recent maturation of mid-infrared diode and quantum cascade lasers, combined with parallel progress in mid-infrared fiber optics, provides the platform from which the field-deployable sensors were designed. State-of-the art signal processing strategies, including calibration-free wavelength modulation spectroscopy, were implemented to tackle the thermo-mechanically harsh environments of a pulse detonation combustor and directconnect scramjet. Time-resolved and spatially-resolved measurements of temperature and carbon oxide species concentrations were demonstrated to provide an in situ metric to evaluate combustion completion for engine development. For shock tube kinetics studies, a multi-band CO2 sensing strategy was developed to provide ppm-level species detection and highly-sensitive measurements of gas temperature with microsecond temporal resolution.


Type of resource text
Form electronic; electronic resource; remote
Extent 1 online resource.
Publication date 2014
Issuance monographic
Language English


Associated with Spearrin, R. Mitchell
Associated with Stanford University, Department of Mechanical Engineering.
Primary advisor Hanson, Ronald
Thesis advisor Hanson, Ronald
Thesis advisor Cappelli, Mark A. (Mark Antony)
Thesis advisor Jeffries, Jay Barker
Advisor Cappelli, Mark A. (Mark Antony)
Advisor Jeffries, Jay Barker


Genre Theses

Bibliographic information

Statement of responsibility R. Mitchell Spearrin.
Note Submitted to the Department of Mechanical Engineering.
Thesis Thesis (Ph.D.)--Stanford University, 2014.
Location electronic resource

Access conditions

© 2014 by Raymond Mitchell Spearrin
This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).

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