Computational Study of Fuel Temperature Impact on Combustion and Pollutant Emissions of a Diesel Engine Fueled with Diesel-Biodiesel Blends

Abstract

The present paper deals with in-cylinder combustion and pollutant formation of biodiesel-diesel blends. A computational fluid dynamics (CFD) study is carried out to assess the performance of a diesel engine fueled with biodiesel-diesel blends. The effect of fuel temperature on various combustion parameters and pollutant emissions is studied. Three fuels are investigated: pure diesel, soybean biodiesel and a blend of 20% soybean biodiesel and 80% diesel (volume percentage). Biodiesel and diesel chemistries are represented by two surrogate mechanisms with 29 and 69 species respectively. The simulations are realized under constant load and speed. A 3D model was first set and validated against experimental results before launching the simulations. Results show that increase in fuel temperature decreases the NOx emissions, while carbon monoxide is increased CO 2 emissions also decrease with the increase of fuel temperature. The peak cylinder pressure is lowered and its location is moved towards the top dead center in all cases. Ignition delay and heat release rate also decrease with the fuel temperature. Exhaust gas temperatures are found to be sensitive to fuel temperature as well. With the lacking experiences conducted, this study gives an insight on the effect of fuel temperature on the combustion and environmental impacts of fuel temperature on diesel engines.