Effects of Intake Port Design and Valve Lift on In-Cylinder Flow and Burnrate

872153

11/01/1987

Event
1987 SAE International Fall Fuels and Lubricants Meeting and Exhibition
Authors Abstract
Content
LDA measurements of the flow in a motored engine near TDC of compression have been obtained, along with burnrate data in a firing engine having a near-central spark plug location. Results are reported for two different intake ports and four intake valve lifts varying from 25% to 100% of full lift. Opposite trends of swirl vs valve lift were found for the two ports, and the rms velocity fluctuation was found to be relatively insensitive to changes in valve lift. Regression analysis of the burn duration data was conducted, with swirl ratio and rms as independent variables. The analysis indicated that burn duration decreases with an increase in swirl ratio and/or rms velocity fluctuation. In light of the experimental findings, a new conceptual model is proposed regarding the effect of valve lift on the dissipation of turbulent velocity via changes in the length scale. And combustion-induced shear in the unburned gas resulting from conservation of angular momentum is hypothesized as a possible mechanism for increased burnrate due to swirl for the case of central ignition.
Meta TagsDetails
DOI
https://doi.org/10.4271/872153
Pages
16
Citation
Kent, J., Haghgooie, M., Mikulec, A., Davis, G. et al., "Effects of Intake Port Design and Valve Lift on In-Cylinder Flow and Burnrate," SAE Technical Paper 872153, 1987, https://doi.org/10.4271/872153.
Additional Details
Publisher
Published
Nov 1, 1987
Product Code
872153
Content Type
Technical Paper
Language
English