Keywords

HTPB, Shock Tube, Speciation, Pyrolysis, Lasers

Abstract

Solid fuel Ramjets (SFRJs) are of interest to the navy and other defense applications because of their high specific impulse, ease of fuel transportation, and low relative cost. Hydroxyl-terminated polybutadiene (HTPB) is one of the main solid fuels of choice for SFRJs, and there is a need for updated chemical kinetic models for the decomposition products of HTPB which will aid in CFD simulations of SFRJs. This work is focused on collecting experimental data for HTPB decomposition products for SFRJ combustor conditions ranging from temperatures of 1000 – 1600 K, pressures of 5 ± 0.5 atm, and rich equivalence ratios of ϕ = 4 and ϕ = 4.76. The mixtures include multiple combinations of the main HTPB decomposition products, ethylene (C2H4), propene (C3H­6), 1,3-butadiene (C4H6), benzene (C6H6), and toluene (C6H5CH3). IR (Infrared) laser measurements and cross-section correlations for ethylene, propene, and 1-3 butadiene were conducted, and a detailed decoupling strategy for removing interference is presented. Decoupled C2H4, C3H6, and C4H6 mole fractions as well as carbon monoxide (CO) are compared to predictions using the AramcoMech3.0 and NUIG 1.3 mechanisms. A sensitivity analysis was performed to determine the most sensitive reactions which would need further investigation for model improvement. A reaction path analysis was performed to understand the important pathways leading to the formation and consumption of ethylene, propene, and 1,3-butadiene. Additionally, the efforts to improve the models were conducted utilizing specific reactions sensitive to ethylene.

Completion Date

2025

Semester

Spring

Committee Chair

Subith, Vasu

Degree

Doctor of Philosophy (Ph.D.)

College

College of Engineering and Computer Science

Department

Mechanical and Aerospace Engineering

Identifier

DP0029370

Document Type

Dissertation/Thesis

Campus Location

Orlando (Main) Campus

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