Effects of thermal expansion on Taylor dispersion-controlled diffusion flames

Fuente: arXiv
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Autori principali: Rajamanickam, Prabakaran, Weiss, Adam D.
Natura: Preprint
Pubblicazione: 2022
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author Rajamanickam, Prabakaran
Weiss, Adam D.
author_facet Rajamanickam, Prabakaran
Weiss, Adam D.
contents A theoretical analysis is developed to investigate the effects of gas expansion due to heat release on unsteady diffusion flames evolving in a pipe flow in which the mixing of reactants is controlled by Taylor's dispersion processes thereby extending a previously developed theory based on the thermo-diffusive model. It is first shown that at times larger than radial diffusion times, the pressure gradient induced by the gas expansion is, in the first approximation, small in comparison with the prevailing pressure gradient driving the flow, indicating that corrections to the background velocity profile are small. The corrections to the velocity components along with the leading-order mixing variables such as the concentrations, temperature and density are solved for a Burke-Schumann flame. Due to the dependence of the effective Taylor diffusion coefficients on the gas density, quantitative and sometimes qualitative departures in predictions from the thermo-diffusive model are observed.
format Preprint
id arxiv_https___arxiv_org_abs_2207_00877
institution arXiv
publishDate 2022
record_format arxiv
spellingShingle Effects of thermal expansion on Taylor dispersion-controlled diffusion flames
Rajamanickam, Prabakaran
Weiss, Adam D.
Fluid Dynamics
A theoretical analysis is developed to investigate the effects of gas expansion due to heat release on unsteady diffusion flames evolving in a pipe flow in which the mixing of reactants is controlled by Taylor's dispersion processes thereby extending a previously developed theory based on the thermo-diffusive model. It is first shown that at times larger than radial diffusion times, the pressure gradient induced by the gas expansion is, in the first approximation, small in comparison with the prevailing pressure gradient driving the flow, indicating that corrections to the background velocity profile are small. The corrections to the velocity components along with the leading-order mixing variables such as the concentrations, temperature and density are solved for a Burke-Schumann flame. Due to the dependence of the effective Taylor diffusion coefficients on the gas density, quantitative and sometimes qualitative departures in predictions from the thermo-diffusive model are observed.
title Effects of thermal expansion on Taylor dispersion-controlled diffusion flames
topic Fluid Dynamics
url https://arxiv.org/abs/2207.00877