Two-Dimensional Modeling of AP/HTPB Utilizing a Vorticity Formulation and One-Dimensional

277 Pages·2017·4.96 MB·English

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Theses and Dissertations
2007-08-16
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Matthew L. Gross
Brigham Young University - Provo
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Gross, Matthew L., "Two-Dimensional Modeling of AP/HTPB Utilizing a Vorticity Formulation and One-
Dimensional Modeling of AP and ADN" (2007). Theses and Dissertations. 1167.
https://scholarsarchive.byu.edu/etd/1167
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TWO-DIMENSIONAL MODELING OF AP/HTPB UTILIZING A
VORTICITY FORMULATION AND ONE-DIMENSIONAL
MODELING OF AP AND ADN

by
Matthew L. Gross

A dissertation submitted to the faculty of
Brigham Young University
in partial fulfillment of the requirements for the degree of

Doctor of Philosophy

Department of Chemical Engineering
Brigham Young University
December 2007

BRIGHAM YOUNG UNIVERSITY

GRADUATE COMMITTEE APPROVAL

of a dissertation submitted by

Matthew L. Gross

This dissertation has been read by each member of the following graduate committee and
by majority vote has been found to be satisfactory.

Date Merrill W. Beckstead, Chair
Date Thomas H. Fletcher
Date Larry L. Baxter
Date Calvin H. Bartholomew
Date William C. Hecker

BRIGHAM YOUNG UNIVERSITY

As chair of the candidate’s graduate committee, I have read the dissertation of Matthew
L. Gross in its final form and have found that (1) its format, citations, and bibliographical
style are consistent and acceptable and fulfill university and department style
requirements; (2) its illustrative materials including figures, tables, and charts are in
place; and (3) the final manuscript is satisfactory to the graduate committee and is ready
for submission to the university library.

Date Merrill W. Beckstead
Chair, Graduate Committee

Accepted for the Department
Larry L. Baxter
Graduate Coordinator

Accepted for the College
Alan R. Parkinson
Dean, Ira A. Fulton College of Engineering
and Technology

ABSTRACT

TWO-DIMENSIONAL MODELING OF AP/HTPB UTILIZING A
VORTICITY FORMULATION AND ONE-DIMENSIONAL
MODELING OF AP AND ADN

Matthew L. Gross
Department of Chemical Engineering
Doctor of Philosophy

This document details original numerical studies performed by the author
pertaining to the propellant oxidizer, ammonium perchlorate (AP). Detailed kinetic
mechanisms have been utilized to model the combustion of the monopropellants AP and
ADN, and a two-dimensional diffusion flame model has been developed to examine the
flame structure above an AP/HTPB composite propellant. This work was part of an
ongoing effort to develop theoretically based, a priori combustion models.
The improved numerical model for AP combustion utilizes a “universal” gas-
phase kinetic mechanism previously applied to combustion models of HMX, RDX, GAP,
GAP/RDX, GAP/HMX, NG, BTTN, TMETN, GAP/BTTN, and GAP/RDX/BTTN. The
universal kinetic mechanism has been expanded to include chlorine reactions, thus

allowing the numerical modeling of AP. This is seen as a further step in developing a
gas-phase kinetic mechanism capable of modeling various practical propellants. The new
universal kinetic mechanism consists of 106 species and 611 reactions. Numerical results
using this new mechanism provide excellent agreement with AP’s burning rate,
temperature sensitivity, and final species data.
An extensive literature review has been conducted to extract experimental data
and qualitative theories concerning ADN combustion. Based on the literature review, the
first numerical model has also been developed for ADN that links the condensed and gas
phases. The ADN model accurately predicts burning rates, temperature and species
profiles, and other combustion characteristics of ADN at pressures below 20 atm.
Proposed future work and modifications to the present model are suggested to account for
ADN’s unstable combustion at pressures between 20 and 100 atm.
A two-dimensional model has been developed to study diffusion in composite
propellant flames utilizing a vorticity formulation of the transport equations. This
formulation allows for a more stable, robust, accurate, and faster solution method
compared to the Navier-Stokes formulations of the equations. The model uses a detailed
gas-phase kinetic mechanism consisting of 37 species and 127 reactions. Numerical
studies have been performed to examine particle size, pressure, and formulation effects
on the flame structure above an AP/HTPB propellant. The modeled flame structure was
found to be qualitatively similar to the BDP model. Results were consistent with
experimental observations. Three different combustion zones, based on particle size and
pressure, were predicted: the AP monopropellant limit, the diffusion flame, and a
premixed limit. Mechanistic insights are given into AP’s unique combustion properties.