Investigation of Droplet Flame Interactions through Experimental and Numerical Approaches

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2023-1-12

Author

Kaya Eyice, Deniz

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Spray combustion applications involve complex phenomena such as atomization, droplet vaporization, mixing, turbulence, chemical kinetics, and the interaction of these processes. In two-phase combustion, one of the fundamental processes is the interaction of a single droplet with a flamelet. Therefore, it is essential to understand the physics of isolated droplet evaporation and its effects on the flame front to study more complex flames. The aim of this study is to investigate droplet evaporation, flame characteristics, and changes in the flame morphology for laminar flames in the presence of droplets via experimental and numerical approaches. The experimental part of the study is conducted in CNRS ICARE, including microgravity experiments to study the flame instabilities of spherically expanding ethanol/air flame in the presence of isolated ethanol droplets using Schlieren method. Additionally, ground experiments are performed to investigate the evaporation characteristics of an ethanol droplet evaporating through flat methane/air flame and the structural changes in propane/air flames due to the passage of an ethanol droplet using optical laser diagnostics including PIV, PTV, ILIDS, Chemiluminescence. In the numerical part of the study, the YALES2 solver is utilized to simulate droplet evaporation under different ambient conditions at elevated temperatures via the Eulerian-Lagrangian approach. In this scope, stationary droplet evaporation is computed at the burnt gas compositions via the Spalding model, as well as the evaporation of a moving droplet through a stagnation flame field via the Abramzon-Sirignano model. Finally, nonreactive and reactive simulations are performed with stagnation burner geometry.

Subject Keywords

Multiphase combustion, Droplet/flame interactions, Flame instabilities, Evaporation

URI

https://hdl.handle.net/11511/101913

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Graduate School of Natural and Applied Sciences, Thesis

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Citation Formats

D. Kaya Eyice, “Investigation of Droplet Flame Interactions through Experimental and Numerical Approaches,” Ph.D. - Doctoral Program, Middle East Technical University, 2023.