Experimental Analysis and 1D Thermo-Fluid Dynamic Simulation of a High Performance Lamborghini V10 S.I. Engine 2005-24-081

This paper describes some recent advances in the field of I.C. engine modeling and simulation, concerning the development and application of a 1D thermo-fluid dynamic research code. An extensive experimental analysis has been concurrently carried out, to support the development and validation of the simulation code. A four-stroke, 10V-cylinder, 5.0 liters automotive S.I. engine has been modeled, in order to predict not only the wave motion in the system and its influence on the cylinder gas exchange process, but also the in-cylinder pressure to get a good prediction of pollutant emission concentration along the exhaust system. The gas composition in the exhaust pipe system is dictated by the cylinder discharge process, after the calculation of the combustion process via a thermodynamic multi-zone model, based on a fractal approach to predict the turbulent combustion. New kinetic mechanisms have been introduced to improve the prediction of NO and CO engine emissions; moreover, a new approach has been implemented, based on a scavenging model, to improve the calculation of engine HC emissions. Predicted results concerning volumetric efficiency, pressure losses, pressure pulses and gas compositions in the exhaust system have been compared with experimental measurements carried out on a configuration of a Lamborghini V10, 5.0 L automotive S.I. engine. These results have pointed out a satisfactory agreement in terms of volumetric efficiency, pressure trends inside the cylinder and exhaust gas composition.