Spray Simulation of n-heptane in a Constant Volume Combustion Chamber Over a Wide Range of Ambient Gas Density and Fuel Temperature

Abstract

Abstract A numerical study was conducted using a constant volume combustion chamber (CVCC) to examine the spray characteristics under diesel engine-like conditions. In this study, spray modelling was implemented into ANSYS FORTE where the initial spray conditions at the nozzle exit and droplet breakups were determined through nozzle flow model and Kelvin-Helmholtz/ Rayleigh-Taylor (KH-RT) model. Simulation conditions were maintained at increasing ambient gas densities (14.8-124 kg/m 3 ) and ambient gas temperature 451 K respectively to demonstrate the non-vaporizing n-heptane spray. Effects of fuel temperature (273-313 K) on spray characteristics were also simulated. Simulation result reveals that the increasing magnitude of ambient gas density decreases the vapor penetration and liquid penetration length at non-vaporizing spray condition. The non-vaporizing spray simulation accuracy was validated by comparing both numerical and experimental results. On the other hand, in the case of lower injection pressure, vapor tip penetration and droplet mass are increased with the decrease of fuel temperature under low ambient temperature and pressure.