Study of Fuel Distribution in Diesel Spray : Effects of Nozzle Diameter, Injection Pressure and Ambient Gas Density

Abstract

The fuel distribution in a diesel spray seriously affects the performance of diesel engines. Nozzle diameter, injection pressure and ambient gas density are important factors, which affect the atomization, penetration and fuel distribution. Therefore, effects of those factors on fuel distribution in a diesel spray were investigated in the cold and quiescent atmosphere. Fuel concentration was deter-mined by the image analysis of shadow photographs of spray. As a result, the following was revealed. In the case of a smaller nozzle diameter and higher injection pressure, the mixing rate of fuel and ambient gas is greater. In similarly designed diesel engines with various power ranges, by normalizing the dimension of engines by nozzle diameter, it is supposed that the shape and fuel distribution of sprays will be similar at same crank angle.