Date of Award

6-16-2016

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Department of Engineering Physics

First Advisor

Kevin C. Gross, PhD.

Abstract

Laminar flames are an important tool in combustion diagnostics with a host of pre-existing experimental research methods. Currently, however, no method captures time-resolved scalar profile estimates of temperature, and major species concentrations with a single measurement. This work provides IFTS with the capability to measure time-resolved 3D imaging of scalar values in laminar axisymmetric flames. This will make IFTS a useful tool for understanding combustion phenomenon, validating chemical kinetic models, verifying numerical simulations, and system performance estimate. Two algorithms are presented. The first reconstructs spectra as a function of flame period. Through selectively averaging over an ensemble of measurements, interferograms representing the scalar fields at t0 can be created. The second improves on traditional tomographic inversion methods to radially resolve multiple scalar values simultaneously in an axisymmetric flame. The combination of these two algorithms was applied to measurements of an unsteady laminar hydrogen flame. Temperature and water concentrations were successfully resolved radially at eight different "snapshot" times in the period of the flames harmonic motion. Measured results compared favorably with previously reported values and CFD simulations. Temperatures agree to within 11% and water concentration values agree to within 19%. This work demonstrates the ability of IFTS to make time-resolved 3-D maps of scalar values of harmonic laminar flame.

AFIT Designator

AFIT-ENP-DS-16-J-018

DTIC Accession Number

AD1054220

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