MEAN VALUE ENGINE MODELING OF A TURBO CHARGED SPARK IGNITED ENGINE - A PRINCIPLE STUDY
J Brugaard, Lars Eriksson, Lars Nielsen · 2001
Object oriented modelling of physical systems is an interesting paradigm, which has the potential to offer reusable models and model components. The aim of this study is to investigate how to build mean value models for automotive engines. MathModelica, a modelling tool for the object oriented modelling language Modelica, is used in this study. Several sub models have been developed for the different parts of the engine. The models cover the air filter, intercooler, throttle, base engine, exhaust system, compressor, turbine, turbine shaft, and volumes. It is shown how the components can be connected to form both turbo charged engines as well as a naturally aspirated engines, which shows that the paradigm is applicable for the modelling and confirms the modelling principle. One problem is the selection of initial conditions for the simulation. Especially when restrictions with low pressure drops are connected between two volumes, the simulation engine has problems finding initial conditions. The models have been compared to measured engine data collected at a test bench in Vehicular Systems laboratory at Linkoeping University. The agreement with measurement data is good and the models work as expected. (A) The report is available on the Internet: http://www.fs.isy.liu.se/Publications/Reports/01_R_2370_JBLELN.pdf.