Published version 2003-01-1798.pdf (1.72 MB)
A comparison of the flow fields generated for spark and controlled auto-ignition
conference contribution
posted on 2014-08-20, 12:00 authored by Graham Pitcher, James W.G. Turner, Graham Wigley, Rui ChenValve timing strategies aimed at producing internal exhaust gas re-circulation in a conventional spark ignition, SI, engine have recently demonstrated the ability to initiate controlled auto-ignition, CAI. Essentially the exhaust valves close early, to trap a quantity of hot exhaust gases in-cylinder, and the fresh air-fuel charge is induced late into the cylinder and then mixing takes place. As a logical first step to understanding the fluid mechanics, the effects of the standard and modified valve timings on the in-cylinder flow fields under motored conditions were investigated. Laser Doppler anemometry has been applied to an optical engine that replicates the engine geometry and different valve cam timings. The cycle averaged time history mean and RMS velocity profiles for the axial and radial velocity components in three axial planes were measured throughout the inlet and compression stroke. The turbulent mixing for the two cases are described in terms of the flow field maps of the velocity vectors, vorticity and turbulence kinetic energy and the integrated tumble ratio as a function of crankangle.
History
School
- Aeronautical, Automotive, Chemical and Materials Engineering
Department
- Aeronautical and Automotive Engineering
Published in
SAE Technical PapersCitation
PITCHER, G. ... (et al.), 2003. A comparison of the flow fields generated for spark and controlled auto-ignition. Presented at: 2003 JSAE/SAE International Spring Fuels and Lubricants Meeting, Yokohama, Japan, 19-22 June.Publisher
© Society of Automotive Engineers of JapanVersion
- VoR (Version of Record)
Publisher statement
This work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/.Publication date
2003Publisher version
Book series
JSAE Paper;20030223Language
- en