Model for transient n-heptane droplet ignition at elevated pressure

The present work deals with transient droplet evaporation and ignition process of an isolated n-heptane droplet at high pressure. The vapor–liquid equilibrium has been described by Peng–Robinson equation of state. In present numerical model, the effects due to elevated pressure, inert species mixing in the liquid phase and thermo-physical properties are considered as variable. The evaporation model has been comprehensively validated with experimental results available in the literature. For the present investigation, the ambient pressure has been varied from $$5$$ to $$80\;{\text{bar}}$$ and at constant ambient temperature of $$1000\;{\text{K}}$$ . The range of diameter was varied from $$0.5$$ to $$2.0\;{\text{mm}}$$ . The ignition delay was found to be strong functions of temperature, pressure and diameter. There is monotonic decrease in the ignition time due to increasing ambient temperature and pressure. At each pressure, there existed a minimum diameter below which ignition does not takes place and this minimum diameter decreases with increase in pressure.