The effect of intake valve alignment on swirl generation in a DI diesel engine

Citation
Ky. Kang et Rd. Reitz, The effect of intake valve alignment on swirl generation in a DI diesel engine, EXP THERM F, 20(2), 1999, pp. 94-103
Citations number
22
Categorie Soggetti
Mechanical Engineering
Journal title
EXPERIMENTAL THERMAL AND FLUID SCIENCE
ISSN journal
08941777 → ACNP
Volume
20
Issue
2
Year of publication
1999
Pages
94 - 103
Database
ISI
SICI code
0894-1777(199910)20:2<94:TEOIVA>2.0.ZU;2-7
Abstract
Two different geometries of the intake valves on the cylinder head of a fou r-valve large-bore diesel engine were compared in terms of their swirl gene ration mechanisms in the cylinder during the intake process. The swirl gene ration level and flow resistance were measured using a swirl meter on a ste ady flow rig and the detailed intake flow structure was studied using LDV m easurements of the in-cylinder bulk flow velocity and turbulence intensity. The effects of changes in the maximum valve lift were also studied for eac h type of valve arrangement. Methods for calculating the swirl moment from the LDV data are presented and discussed by comparing with the swirl meter results. It was found that the aligned valve port arrangement (valves locat ed at equal distances from the symmetry axis) generates higher swirl due to its eccentricity with respect to the intake port. In an inclined valve por t engine (valves at different distances from the symmetry axis), increasing the maximum valve Lift was found to improve the swirl generation capabilit y significantly, even though it generated less swirl overall due to swirl c ancellation at low valve lifts. (C) 1999 Elsevier Science Inc. All rights r eserved.