Research for Nonlinear Turbulent Combustion Control in Common Rail Diesel Engine by New Injection Control Strategies

Abstract

To control cylinder pressure in diesel engine multiple injections is presented by using new control strategy. The improvements of the solenoid injector and of the electronic control unit of the present common rail (CR) injection system allow the use of multiple sequential injections. Two injections are included in the new injection strategies. The first injection is the pre-injection and at 33 CAD (crank angle degree) BTDC (before top dead center) , whose duration time is 110 ¿s. The second injection is the main injection at five different angles, whose duration time is 1000 ¿s. Thus, little diesel is ignited first and the temperature is decreased in the cylinder. Much diesel is ignited later and large torque is got. This paper describes the experimental results obtained with the application of a prototype of this advanced common rail system to a 4JB1 eight-valve four-cylinder engine. Multidimensional modeling of the combustion process and heat release rate was also employed to interpret the trends observed in the experiments.