A new advanced turbocharger model ant its application in a powertrain model to simulate real driving operations


Abstract: An accurate prediction of the complex thermodynamic behavior of combustion engines is getting more and more important in powertrain research and development. Both the number and the meaning of components have increased rapidly in modern engines, and its models are mainly based on completely different approaches due to the differ-ent mechanical, aerodynamical, thermal or chemical processes in distinct temporal and spatial conditions. 1D engine process simulation is for a long time the basis to simulate the thermodynamics of combustions engines. Engine components are represented by specific, individual models. As an example the model of the turbocharger is normally based on simple maps obtained on component test benches. At TU Berlin new meth-ods have been developed to allow a completely new approach to model the turbo-charger behavior. Besides of aerodynamics, new options of thermal and pulsation characteristics as well as friction losses are included. Among other improvements the real isentropic turbine efficiency is obtained using new measurement technologies for the exhaust gas temperature. Moreover there are new ways to experimentally identify and model heat transfer of the turbocharger and its gas pulsations. The new turbo model can be applied in 1D engine simulations of driving cycles including the compu-ting of a more realistic fuel consumption. One specific example is the more accurate prediction of the transient heating of components during engine startup that allows realistic input data for aftertreatment components. Finally more options for other engine compoents in powertrain models are discussed.