Effect of Sauter mean diameter on the combustion related parameters in heavy-duty diesel engines

A mathematical model of combustion process in a diesel engine has been developed according to the theory of the chain reactions for the higher hydrocarbon compounds. The instantaneous rates of fuel vaporization and combustion are defined by the current values of temperature, pressure, concentration of fuel vapors, overall diffusion rate, fuel injection rate, and mean fuel droplet size in terms of the Sauter mean diameter (SMD). Numerical experiments have been carried out for investigating the interdependency between various combustion-related parameters. Specifically, the effect of fuel droplet size (in terms of SMD) on the subsequent combustion parameters, such as pressure, temperature, thermodynamic properties of air/gas mixture, heat transfer, fuel vaporization, combustion rate, current air/fuel ratio, and gas mixture composition have been investigated. In addition, the integral indicator parameters of the engine, such as mean indicated pressure, peak pressure, compression pressure, and specific fuel consumption have been analyzed. The results show very good agreement with the available data on heavy-duty diesel engines.