Abstract

As industry transitions to a net-zero carbon future, turbulent premixed combustion will remain an integral process for power generating gas turbines and are also desired for aviation engines due to their ability to minimize pollutant emissions. However, accurately predicting the behavior of a turbulent reacting flow field remains a challenge. To better understand the dynamics of premixed reacting flows, this study experimentally investigates the evolution of turbulence in a high-speed bluff-body combustor. The combustor is operated across a range of equivalence ratios from 0.7-1 to quantify the role of heat release and flame scales on the evolution of turbulence as the flow evolves from reactants to products. High-speed particle image velocimetry and CH* chemiluminescence imaging systems are simultaneously employed to quantify turbulent flame and flow dynamics. The results demonstrate that the flame augments turbulence fluctuations as the flow evolves from reactants to products for all cases. However, turbulence fluctuations increase monotonically with the heat of combustion and corresponding turbulent flame speed. Nondimensional spatial profiles of turbulence are used to develop a correlation to predict the increase in turbulent fluctuations in an extended progress variable space. A Reynolds Averaged Navier Stokes (RANS) decomposition is also explored to better characterize the effects of heat release on turbulence evolution dynamics. The correlations and RANS decomposition can guide modeling capabilities to better predict confined turbulent reacting flows and accelerate design strategies for premixed turbines with carbon-free fuels.

Notes

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Graduation Date

2023

Semester

Spring

Advisor

Ahmed, Kareem

Degree

Master of Science in Aerospace Engineering (M.S.A.E.)

College

College of Engineering and Computer Science

Department

Mechanical and Aerospace Engineering

Degree Program

Aerospace Engineering; Thermofluid Aerodynamic Systems Design and Engineering

Identifier

CFE0009522; DP0027527

URL

https://purls.library.ucf.edu/go/DP0027527

Language

English

Release Date

May 2023

Length of Campus-only Access

None

Access Status

Masters Thesis (Open Access)

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