Eventos Anais de eventos
ENCIT 2016
16th Brazilian Congress of Thermal Sciences and Engineering
A Numerical Study on the Effects of Preferential Diffusion in Ethanol Laminar Reactive Flows
Submission Author:
Albino Leiroz , RJ , Brazil
Co-Authors:
Rafael Leitão, Ricardo Soares, Marcelo Colaco
Presenter: Ricardo Soares
doi://10.26678/ABCM.ENCIT2016.CIT2016-0498
Abstract
The present work evaluates the effects of preferential diffusion in axisymmetric confined reactive flow. The analysis of combustion reaction is conduct for two different fuels, Methane and Ethanol, with Air as the oxidizing agent. A global, single step, irreversible with infinitely fast rate reaction is considered as a model for the chemical kinect mechanism. The preferential diffusion is evaluated using the formulation proposed in the literature, which uses the generalized mixture fraction and excess enthalpy as conserved scalar, extending thus the classical formulation for non-unitary Lewis numbers. Temperature variation of thermophysical properties is considered in the developed model. The quantities of interest of reactive flow are obtained using the Finite Volume Method in a structured mesh. The results are improved applying an adaptive grid generation scheme which allows increasing resolution in regions near the flame and solid walls, where large temperature gradients are expected. The results are obtained for different numbers of Lewis as much for fuel and oxidizer, and show the general behavior of the speed, temperature, mass fraction and mixture fraction profiles influenced by this parameter. The results are compared with the case of the unitary Lewis number.
Keywords
Preferencial Difusion, Diffusion Flame, Numerical Methods, Combustion, Biofuels
