Browse Publications Technical Papers 981048
1998-02-23

Effects of Intake Ports on In-Cylinder Flow and Lean Combustion in a 4-Valve Engine 981048

Intake-generated in-cylinder flow and subsequent combustion characteristics were studied respectively in a 4-valve spark ignition engine. The flow characteristics of four-valve cylinder head were examined under a steady flow condition for intake ports with three different entry angles; θ=15°, 20° and 25°. The velocity and angular momentum distributions in the tumble adaptor were measured with PIV (Particle Image Velocimetry). Subsequent effects of tumble flow generated by various intakes ports on the lean burn characteristics were also investigated. The lean burn performances were examined in a four-valve pentroof engine. The combustion duration under lean mixture conditions was calculated by heat release analysis of the pressure trace.
The results show that flow structure is complicated by valve interference at low valve lift. As the flow rate in the direction of tumble increased with increasing valve lift, in-cylinder flow pattern changed to large vortex structure with tumble direction. Intake ports with different entry angles have different tumble centers. Therefore there is a correlation between the stronger tumble during induction and faster, more stable combustion under lean mixture conditions. Combustion duration also revealed faster flame propagation in the stronger tumble port under lean mixture conditions, than that in weak tumble port. By comparing tumble intensities and combustion duration, the design of intake port with the optimal entry angle was discussed.

SAE MOBILUS

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

Access SAE MOBILUS »

Preview Document Add to Cart
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:
TECHNICAL PAPER

CFD Simulations of Intake Port Flow Using Automatic Mesh Generation: Comparison With Laser Sheet, Swirl and LDA Measurements for Steady Flow Conditions

980129

View Details

TECHNICAL PAPER

Study of Ignition Processes of a Lean Burn Engine using Large-Eddy Simulation

2019-01-2209

View Details

TECHNICAL PAPER

An Experimental Investigation on a New Squish Jet-Turbulence Combustion Chamber for SI Engine

1999-01-3664

View Details

X