S. Mousavi - School of Mechanical Engineering, College of Engineering, University of Tehran, Tehran, Iran‎
A. Nejat - School of Mechanical Engineering, College of Engineering, University of Tehran, Tehran, Iran‎
S. S. Alaviyoun - Mechanical Engineering, K.N. Toosi University of Technology and Design Department of ‎Iran Khodro Powertrain Company, Tehran, Iran
M. Nejat - Mechanical Engineering, Iran Khodro Powertrain Company, Tehran, Iran

Following the global environmental concerns, many automobile manufacturers intend to produce smaller ‎engines, aiming to lower emissions and fuel consumption. As compensation for performance reduction, these ‎engines are equipped with turbochargers. One of the challenges is to select the right turbocharger for a specific ‎engine. In this regard, an integrated zero-dimensional turbocharger and engine simulation program is ‎developed, employing a quasi-steady compressible flow method. The program gives the designer the ‎possibility of observing the performance of different compressor-turbine combinations on an internal ‎combustion engine. Engine details such as fuel, cylinder geometry, heat transfer conditions, valve timing, and ‎spark timing are considered within the engine modeling, and the designer can investigate their effects on the ‎overall performance of the system. Compressor and turbine performances are predicted by their previously ‎provided performance maps (steady-state characteristic curves) and special inter- and extrapolation methods. ‎A new algorithm for turbocharger matching is suggested, and its logics, basic convergence loops, and ‎thermodynamic equations have been described in detail. A database containing digitized compressor and ‎turbine maps and details provided by different manufacturers is created and integrated into the program. An ‎existing turbocharged engine has been tested and also simulated by the program. The accuracy of the program ‎results is evaluated by comparing them with experimental results. The maximum error of modeling the engine ‎and the whole simulation is ۱.۵% and ۱۶%, respectively. Two other compressor-turbine combinations have ‎been evaluated using the program, one of which is suggested as an alternative‎‎.

Internal combustion engine, Turbocharger matching, Engine ‎performance simulation, Zero, dimensional simulation, Engine downsizing‎