Transient gas phase interaction effects during droplet-stream combustion

Abstract

Gas-phase transient effects during the combustion of an infinite linear array of droplets are studied in the limit of infinite Damköler number and in the absence of surrounding convective effects. The present study stems from the quantification of truncation-distance effects on the droplet mass vaporization rate, flame position and flame shape in quasi-steady numerical simulations. The solution domain is initially split into near and far-field subdomains. Within each subdomain, analytical grid generation techniques are applied allowing the development of appropriate finite-difference expressions, the control of grid point distribution and the treatment of outflow boundary conditions. The interdroplet distance effect is studied and results for the droplet mass vaporization rate and flame behavior are presented. The results show the existence of different flame regimes ranging from isolated to merged flame conditions and similar vaporization rate evolution for different interdroplet distances

Comparative Study of Equilibrium and Nonequilibrium Evaporation Models for Vaporizing Droplet Arrays at High-Pressure

“…The latter have become increasingly important in modern propulsion systems due to the fact that vaporization occurs under conditions of large departure from equilibrium, measured in terms of temperature and/or pressure difference between the droplet and the carrier gas. The literature in this area is now extensive, addressing these problems at various levels of complexity (Imaoka and Sirignano, 2005;Leiroz and Rangel, 1995;Wong and Lin, 1992;Sangiovanni and Labowsky, 1982). However, as yet no conclusive evidence has been achieved due to a lack of reliable experimental data.…”