Validating Phenomenological Smoke Model at Different Operating Conditions of DI Diesel Engines

A new phenomenological model that was published in ref [1] encompasses the spray and the wall interaction by a simple geometrical consideration. The current study extends this earlier work with investigations made on 16 different engines from 6-engine families of widely varying features applied to off-highway as well as on-road duty. A dimensionless factor was introduced to take care of the nozzle hole manufactured by hydro-erosion, (HE) as well as the conical shape of the nozzle hole (K factor) in case of valve closed orifice type of nozzles. The smoke emitted from the wall spray formed after wall impingement is the major contributor to the total smoke at higher loads. As the fuel spray impinges upon the walls of the combustion chamber, its velocity decreases. This low velocity jet contributes to the higher rate of the smoke production. Therefore, the combustion bowl geometry alongwith injection parameters play a significant role in the smoke emissions. The satisfactory comparison of predicted and observed smoke over the wide range of operation demonstrated applicability of the model in simulation study of combustion occurring in DI diesel engines.