Browse Publications Technical Papers 2003-01-0629

Dilution Interest on Turbocharged SI Engine Combustion 2003-01-0629

This paper presents a prospective combustion study about dilution effects on turbocharged SI engine at full load. It proposes a comparative analysis between lean burn and cooled exhaust gas recirculation (EGR) operation as knock improvement artifice in substitute of enrichment.
The study was led on a four cylinder 2L engine on stationary test bench. A specific EGR circuit was designed in order to achieve high control of the temperature and mass flow of the recirculated gas. Thanks to instantaneous pressure cylinder transducers, a combustion analysis was carried out using an home-made code. 1-D simulations (WAVE code) were used to complete the analysis on volumetric efficiency and turbocharger behaviour.
A real advantage of cooled EGR was observed in the study compared to lean burn or enrichment in terms of performance, heat exchange and specific fuel consumption.
The coupling between engine and turbocharger presents a double synergy in terms of combustion and volumetric efficiency for the cooled EGR.
On the combustion side, this double synergy offers a high dilution potential and a reduction of the internal residual gas fraction. Main consequences are knock resistance and indicated efficiency improvement.
By limiting the pressure before turbine, this method also improves volumetric efficiency and increases the compressor pressure ratio in order to stay in better efficiency areas of the turbocharger.


Subscribers can view annotate, and download all of SAE's content. Learn More »


Members save up to 16% off list price.
Login to see discount.
Special Offer: Download multiple Technical Papers each year? TechSelect is a cost-effective subscription option to select and download 12-100 full-text Technical Papers per year. Find more information here.
We also recommend:

Replacing Fuel Enrichment in a Turbo Charged SI Engine: Lean Burn or Cooled EGR


View Details


Combined Benefits of Variable Valve Actuation and Low-Pressure EGR on SI Engine Efficiency Part 1: Part Load


View Details


Potential ESC Performance of a Multi-Cylinder Heavy Duty PPC Truck Engine: System Simulations based on Single Cylinder Experiments


View Details