ORCID
0009-0005-6823-3219
Keywords
ammonia, zero carbon fuel, gas turbines, laser diagnostics, emissions
Subject Categories
Aerospace Engineering | Chemical Engineering | Heat Transfer, Combustion | Mechanical Engineering
Abstract
Ammonia-hydrogen rich-burn, quick-quench, lean-burn (RQL) combustion is of interest for low-emissions gas turbine (GT) applications. In this dissertation, a scanned-wavelength laser absorption spectroscopy (LAS) diagnostic system was developed to measure species concentrations and gas temperature in an atmospheric-pressure toroidal jet-stirred reactor (TJSR) operating with ammonia/hydrogen/air mixtures. Fuel ammonia fractions from 3–100% and fuel-air equivalence ratios from 0.27–1.4 were examined, spanning ϕ = 0.27–0.67 for the lean stage and ϕ = 1.1–1.4 for the rich stage. These conditions were chosen to represent the rich- and lean-burn regimes of the RQL gas turbine concept. Scanned-wavelength LAS was used to measure gas temperature, water vapor at 1936.21 cm-1 and 1937.94 cm-1, nitric oxide at 1937.02 cm-1, and ammonia at 962.17 cm-1 in the reactor exhaust. The experimentally measured H₂O, NO, NH3 and temperature trends were compared against predictions from two detailed chemical kinetic mechanisms, UCF and NUIG 2023, using a reactor network model. Both mechanisms capture the overall water formation trends reasonably well across the lean and rich operating ranges, while NO is consistently underpredicted in both stages—modestly under lean conditions and severely under rich conditions, where both mechanisms predict near-zero NO across most of the tested range. Predicted exhaust temperatures are generally higher than LAS measurements in the lean stage, while in the rich stage the two are in closer agreement, particularly for the higher-NH3 blends.
These results provide fundamental experimental benchmarks for both fuel-rich and fuel-lean NH3/H2 combustion under RQL-relevant conditions. This high-fidelity data set is intended to support continued development and validation of chemical kinetic mechanisms for ammonia-fueled gas turbine applications.
Completion Date
2026
Semester
Summer
Committee Chair
Vasu, Subith
Degree
Doctor of Philosophy (Ph.D.)
College
College of Engineering and Computer Science
Department
Mechanical and Aerospace Engineering
Format
Document Type
Thesis
Language
English
Release Date
8-15-2027
STARS Citation
Ahmed, Marzuqa, "Development And Application Of A Laser Diagnostic System For Ammonia, Water, And Nox Measurements In A Toroidal Jet Stirred Reactor" (2026). Graduate Studies Theses and Dissertations 2026. 222.
https://stars.library.ucf.edu/gradstudies_etd_2026/222
Included in
Aerospace Engineering Commons, Chemical Engineering Commons, Heat Transfer, Combustion Commons
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