Analysis and dynamic calibration of the transient of an SI-engine equipped with turbocharger

Abstract

Transient is considered an important operation mode of an engine since most of its working cycles happen in this mode. In this paper, GT-Power software is used to model the engine and the turbocharger; moreover, the experimental results from the IPCO Company are used for validation and calibration. The simulation is calibrated for the engine's steady state in the part-and full-load conditions. Then, since the transient simulation cannot be performed based on the steady-state settings, the engine transient simulation is calibrated. Upon the performed simulation, the calibration differences of the transient and the steady state are investigated. These differences are analyzed during four processes of combustion, injection, heat transfer in the exhaust manifold and the turbocharger performance; then the various parameters' effect on the engine transient are studied. The considered transient is the one during which the engine load increases with the throttle opening at a constant engine speed. It is concluded that the produced maps of the combustion and injection parameters, which are achieved from the quasi-steady conditions, can properly predict these parameters' behavior. However, the turbocharger performance and the heat transfer inside the exhaust manifold must be calibrated, transiently. With this procedure for model calibration, the error between the model and the experimental results were decreased significantly. For example, in the speed of 1900 rpm, the error between the model and the experimental data for transient simulation is reduced from 1.57 to 0.18%. The studied engine is 1.65 L EF7-TC which is a spark ignition engine equipped with a turbocharger.