Degree Type

Thesis

Date of Award

2017

Degree Name

Master of Science

Department

Chemical and Biological Engineering

Major

Chemical Engineering

First Advisor

Rodney O. Fox

Abstract

The focus of this work was to study the structure of multiple turbulent flame configurations using

the steady laminar flamelet model (SLFM) coupled with Reynolds-averaged Navier-Stokes

(RANS) and large eddy simulation (LES) transport equations. A detailed chemistry mechanism

(GRI 3.0) was used in the formulation of the flamelet library. In addition, a probability density

function (PDF) approach was used to generate the flamelet table in terms of its mean quantities

2 ( , , ) ZZ as a function of the Favre-averaged mixture fraction, mixture fraction variance, and

the scalar dissipation rate. A beta PDF was assumed for mixture fraction and a delta function

distribution for the scalar dissipation rate. This approach ensured that finite-rate chemistry effects

were introduced in the turbulent flow calculations. Radial mean and RMS distributions of

temperature, mixture fraction, and species mass fractions were predicted at different axial locations

for Sandia D and B-1 flames. The simulation results were validated against experimental data

(Barlow & Frank 2007; Sevault et al. 2012). The validation study showed that LES/SFLM has

better mean and RMS distributions for the B1 flame compared to RANS-SLFM. This was due to

the fact that LES has a better representation of mixing than RANS since it resolves the large

turbulent scales, which contain the largest amount of kinetic energy and control the mixing process

in turbulent non-premixed combustion. Nonetheless, RANS-SLFM produced an acceptable mean

profile for the Sandia D-flame for relatively low computational expense. However, mean radial

profiles of minor species were not accurately predicted for either flame using RANS-SLFM, while

good agreement was obtained with LES-SFLM

DOI

https://doi.org/10.31274/etd-180810-5101

Copyright Owner

Adel Alghamdi

Language

en

File Format

application/pdf

File Size

82 pages

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