Modified multipurpose reduced chemistry for ethanol combustion

Theoretical and numerical analysis of the evaporation of mono- and multicomponent single fuel droplets

“…This possibility, very real even for low ambient temperature, has been considered elsewhere (Millán-Merino 2020; Millán-Merino et al. 2020). This simple configuration is especially suited for testing and improving the fundamental understanding of droplet vaporization.…”

“…Pure nitrogen atmospheres are typically employed in droplet vaporization experimental set-ups, and then in numerical simulations, to avoid chemical reactions that could lead to uncontrolled variations in the temperature and concentration fields or even produce autoignition during droplet vaporization. This possibility, very real even for low ambient temperature, has been considered elsewhere (Millán-Merino 2020;Millán-Merino et al 2020). This simple configuration is especially suited for testing and improving the fundamental understanding of droplet vaporization.…”

“…Mass diffusion time for β phase Motivated by the order-of-magnitude analysis shown above, in the present work, we assume that the gas phase is quasi-steady but we consider the full transient problem for the liquid phase, as was already stated for the formulation in § 2. This approach will be compared later with the solution obtained using the full transient formulation for both gas and liquid phases described in Millán-Merino et al (2020).…”

“…This gas contains a high content in water vapour that, in addition to ambient humidity, will affect droplet vaporization, as we show below. These changes can lead to variations in the combustion properties (Millán-Merino 2020;Millán-Merino et al 2020) In figure 7 we show the effect of both the initial volumetric water content V = V H 2 O /V droplet and ambient relative humidity H, defined above in (5.1), on the evolution of a droplet evaporating in an inert nitrogen atmosphere at ambient temperature T ∞ = 293 K. According to the order-of-magnitude analysis presented in (4.2), the small value of the parameter t C /t R = 0.002 1 anticipates a negligible influence of radiation. (0, 0.24, 0.44).…”

“…We assume that at the droplet, of uniform temperature and composition, is suddenly placed unperturbed in the gaseous ambient: Notice that, because of the quasi-steady assumption for the gas phase, it is not necessary to smooth the initial condition in the gas phase near the droplet interface, as was done in a previous work (Millán-Merino et al. 2020) to avoid numerical instabilities. The comparison between both approaches in this work provides further validation for the approximation used there.…”