THE DYNAMIC BEHAVIOR OF A DIESEL ENGINE.

In modeling the dynamic behavior of a pump/pipeline system, a subject of previous papers at the WEDA/TAMU conferences. The diesel engine is modeled very simple as a first order system. The time constant of the first order system determines the time delay between changing a set point for the revolutions of the diesel and the change of the real revolutions of the diesel engine. This modeling is too simple to describe the real behavior of the diesel engine. More complex models exist, but in general they are too complex, describing the full thermodynamic behavior of diesels. Those models are used for the simulation of engine rooms. So there is a need for a model that is more advanced then a first order system and less advanced then the very complex models. Such a model has been derived, based on the Seiliger (thermodynamic) process. The results of the model show that the diesel engine behaves like a second order system when operating in the governor area and more like a first order system in the constant torque (overload) area. This model will be incorporated in the pump/pipeline model. The paper will give a detailed description of this new model, including the MATLAB model and give examples of the response of the model