Browse Publications Technical Papers 2005-01-0690
2005-04-11

Investigation of a 2-step Valve Train and its Influence on Combustion by Means of Coupled CFD Simulation 2005-01-0690

A 2-step valve train offers a cost effective alternative to fully variable valve trains. Using the small valve lift, which is usually combined with an early intake closing strategy, reduced pumping losses are opposite to decreasing combustion efficiency due to lower charge motion. To work out the trade off between these two effects an extensive coupled CFD investigation is performed. The 1-D engine model delivering the pumping losses is complemented by an empirical combustion model, that relates combustion duration with residual trapped gas content. The model ensures right prediction of fuel economy. Additionally the influence of a small intake valve event on charge motion can also be demonstrated by 3-D in-cylinder flow simulation.

SAE MOBILUS

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

Access SAE MOBILUS »

Members save up to 18% 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:
TECHNICAL PAPER

Integrated Hydro-Mechanical Simulation of a Cam-Rocker-Unit Injector System to Address Noise and Vibration Issues

2006-01-0887

View Details

TECHNICAL PAPER

Development Process to Optimize Design and Performance of Small Gasoline Engines

2007-32-0093

View Details

TECHNICAL PAPER

Friction Reduction - the Engine's Mechanical Contribution to Saving Fuel

2000-05-0160

View Details

X