Date of Award

Fall 2014

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Mechanical & Aerospace Engineering

Program/Concentration

Aerospace Engineering

Committee Director

Kareem Ahmed

Committee Member

Shizhi Qian

Committee Member

Xiaoyu Zhang

Call Number for Print

Special Collections; LD4331.E56 M24 2014

Abstract

The concept of the Pulse Detonation Engine (PDE) has been of interest for centuries. The issue was originally studied to understand flame propagation in mine shafts after explosions due to methane buildup. The flames would travel down the shafts, transitioning to turbulent flames due to the roughness of the shaft walls, and accelerate to detonation, delivering powerful, destructive forces. The potential for efficient energy production was noticed, and the theory behind flame propagation was later applied to developing propulsion systems. Recently, researchers have begun to understand the full potential of PDEs to efficiently produce an immense amount of thrust due to generated detonation wave. Numerous experimental PDE facilities have been engineered which successfully achieve detonation through the use of solid obstructions to induce turbulent combustion. These obstacles create recirculation regions within the propagating flame and reflect acoustic waves, both of which contribute to turbulence production within the flame. Turbulence production is important because it increases the surface area of the flame, which causes the flame to accelerate and achieve detonation more quickly. Despite success, the use of a solid object has numerous drawbacks including pressure losses and heat soaking. An alternate solution to induce turbulence is through the use of a fluidic-based jet. The goal of the current research is to investigate the fundamental physics governing the interaction of a laminar deflagrated flame with a fluidic jet. The fluidic jet is an efficient mechanism for inducing turbulence and flame acceleration relative to solid obstacles. The control of jet velocity provides dynamic control of turbulent production mechanisms. Additionally, the jet eliminates pressure losses and heat soak effects induced by obstacles. A PDE experimental setup is utilized in developing an understanding of the jet-flame interaction. The effects of varying equivalence ratios of methane and air for the flame and jet, as well as varying jet momentum ratios, on the interaction are studied. The facility is constructed of optically clear acrylic, which allows for analysis of the interaction with non-invasive testing methods including Schlieren imaging, Particle Image Velocimetry (PIV), and Chemiluminescence. These techniques provide qualitative and quantitative data pertaining to the interaction, which are used to define the physics of the interaction.

Rights

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DOI

10.25777/hebk-j392

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