Abstract
The ignitability of a fuel droplet in a reactive oxygen/fuel-vapor/inert environment simulating the spray interior is studied using large activation energy asymptotics. The cold boundary difficulty is removed by recognizing that ignition occurs at a finite radial distance which can be physically prescribed. A set of universal ignition Damköhler number curves have been numerically generated and subsequently fitted to yield an explicit ignition criterion suitable for incorporation into spray modeling.