Ignition and combustion characterization of single nitromethane and isopropyl nitrate monopropellant droplets under high-temperature and quasi-steady conditions

摘要

The dynamics of reacting droplets of the monopropellants nitromethane (NM) and isopropyl nitrate (IPN) are compared to those of methanol. Single droplets of these three fuels were burned in steady flow high-temperature conditions, produced by a McKenna flat-flame burner. Coherent anti-Stokes Raman scattering (CARS) thermometry was employed to characterize the temperature of the flow-field experienced by the droplets. Ignition delay times and droplet burning rates were obtained for droplets with initial diameters ranging between 0.4 and 1.4 mm. Droplet dynamics such as deformation, puffing, stripping and microexplosions are qualitatively discussed. Lastly, the D-2 law and the hybrid combustion model are applied to IPN and NM droplets, and the experimental mass burning rates are compared to theoretical predictions. (C) 2019 The Combustion Institute. Published by Elsevier Inc. All rights reserved.