Bauer F, Bräuer P, Wilke M, Will S, Grauer SJ (2023)
Publication Type: Journal article
Publication year: 2023
Article Number: 112730
DOI: 10.1016/j.combustflame.2023.112730
During the formation of soot, the particles undergo a fine structural transformation, akin to graphitization, from “young” to “mature” soot. This ageing process is accompanied by a change in optical properties, which manifests in the soot optical band gap and dispersion exponent, Eg and ζ. Although both quantities are regularly determined via broadband extinction measurements, they have a nonlinear relationship to the local extinction spectrum, so line-of-sight integrated measurements introduce errors into estimates of Eg and ζ. We report the development of an absorption tomography sensor that enables 2D in situ mapping of Eg and ζ. Our sensor employs broadband back-illumination, fiber-coupled collection optics, and an imaging spectrograph to simultaneously acquire 24 spectrally-resolved absorption signals, suitable for tomographic reconstruction. We perform proof-of-concept experiments to characterize soot formation in non-premixed steady flames from a Gülder burner, using ethylene and propane as fuels. Reconstructions based on axisymmetric and non-axisymmetric absorption tomography are compared, and we explore how our sensor can be adapted to perform temporally-resolved measurements in a turbulent flame.
APA:
Bauer, F., Bräuer, P., Wilke, M., Will, S., & Grauer, S.J. (2023). 2D in situ determination of soot optical band gaps in flames using hyperspectral absorption tomography. Combustion and Flame. https://dx.doi.org/10.1016/j.combustflame.2023.112730
MLA:
Bauer, Florian, et al. "2D in situ determination of soot optical band gaps in flames using hyperspectral absorption tomography." Combustion and Flame (2023).
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