Numerical Modeling Of Steady Burning Characteristics Of Spherical Ethanol Particles In A Spray Environment

摘要

A numerical study of steady burning of spherical ethanol particles in a spray environment is presented. A spray environment is mod-eled as a high temperature oxidizer stream where the major prod-ucts of combustion such as carbon dioxide and water vapor will be present along with reduced amounts of oxygen and nitrogen. The numerical model, which employs variable thermophysical properties, a global single-step reaction mechanism, and an opti-cally thin radiation model, has been first validated against pub-lished experimental results for quasi-steady combustion of spherical ethanol particles. The validated model has been employed to predict the burning behavior of the ethanol particle in high temperature modified oxidizer environment. Results show that based on the amount of oxygen present in the oxidizer the burning rate constant is affected. The ambient temperature affects the burning rate constant only after a sufficient decrease in the ox-ygen content occurs. In pure air stream, ambient temperature var-iation does not affect the evaporation constant. Results in terms of burning rates, maximum temperature around the particle, and the evaporation rate constants are presented for all the cases. The variation of normalized Damk?hler number is also presented to show the cases where combustion or pure evaporation would occur.