Abstract
The extinction of an envelope flame at the forward stagnation-point of a liquid fuel droplet due to forced convection is numerically investigated using a quasi-steady model. The droplet is oxidizing within an air stream at atmospheric pressure and under zero-gravity conditions. Combustion is modeled using finite-rate chemical kinetics and a one-step overall reaction. Results for extinction velocity as a function of droplet diameter are presented for a n-heptane droplet in an environment at 300K. Experimental results available in the literature for various fuels, and different droplet diameters, compare well with the numerical predictions for n-heptane. A linear dependence of the extinction velocity as a function of droplet diameter constitutes the present state of knowledge. This study predicts a nonlinear dependence for small diameters (d<2mm), and a linear dependence only for large diameters(d>2mm).
