An Experimental Study on the Fuel Spray Distribution and Combustion Characteristics in a Diesel Engine with Side-Injection System

The fuel spray distribution and combustion characteristics in side-injection system have been investigated by making use of the special test engine equipped with a variable angle swirler. As the results of experiments, following items have been clarified. In side-injection system, higher swirl intensity is necessary at combustion stage than central-injection system. Therefore the swirl acceleration by piston bowl during compression stroke is effective to improve the combustion characteristics. For the optimization of combustion system, it is important to find out the optimum combination of shape of combustion chamber and initial swirl intensity. When the residual fuel is used, optimization of shape of combustion chamber becomes more important. For example, spherical bowl type combustion chamber can achieve better specific fuel consumption with smaller initial swirl intensity than flat-bottom bowl type.