Abstract
Coal dust explosions can be hazardous; however, they can also generate a significant rise in stagnation pressure if adequately harnessed. Rotating detonation engine combustors seek to take advantage of the stagnation pressure rise phenomenon in a more sustained and controlled manner via confinement to a physical annulus, leading to increased overall thermodynamic efficiency. This investigation presents an analysis of detonations fueled by Carbon Black, a solid particulate consisting of virtually pure carbon molecules and lean Hydrogen-Air mixtures. As was previously realized with the addition of Carbon Black, an increase of operability limits and detonation velocities over that of a pure Hydrogen-Air interaction exist. For all testing conditions, the total equivalence ratio is held at f = 1, while the fuel mixture's carbon mass fraction is increased from 0 – 0.7. Total mass flow injected into the annulus remained constant (?0.415 kg/s). Detonation wave velocities are extracted from high-speed imaging through applying a Discrete Fourier Transform algorithm to determine changes to speed when Carbon Black particles are introduced. As a result, due to the addition of Carbon Black as an auxiliary fuel source, detonations were formed instead of deflagrations in operating conditions where one would expect deflagrations at the same Hydrogen-Air equivalence ratios without Carbon Black addition. The detonation formation provides evidence that the coal particles are reacting within the detonation wave in a large enough capacity to aid in forming and supporting a detonation wave within the annulus. The detonation wave velocities were found to decrease with hydrogen's incremental replacement with coal particles while maintaining a constant global equivalence ratio. Whereby, through a theoretical comparison of the heat of combustion as computed from the experimentally derived detonation wave velocities, a linear relationship of the two was shown to exist. Therefore, the heat of combustion has the potential to describe an operational limit to sustaining a detonation wave.
Notes
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Graduation Date
2021
Semester
Spring
Advisor
Ahmed, Kareem
Degree
Doctor of Philosophy (Ph.D.)
College
College of Engineering and Computer Science
Department
Mechanical and Aerospace Engineering
Degree Program
Aerospace Engineering
Format
application/pdf
Identifier
CFE0008467; DP0024143
URL
https://purls.library.ucf.edu/go/DP0024143
Language
English
Release Date
May 2024
Length of Campus-only Access
3 years
Access Status
Doctoral Dissertation (Open Access)
STARS Citation
Dunn, Ian, "Solid Materia and Multiphase Detonations Wave Dynamics in a Rotating Detonation Engine" (2021). Electronic Theses and Dissertations, 2020-2023. 496.
https://stars.library.ucf.edu/etd2020/496