Paper-Turb_Premixed_Combustion-rev5.pdf (864.46 kB)

Numerical evaluation of combustion regimes in a GDI engine

Download (864.46 kB)
conference contribution
posted on 09.06.2017, 12:59 by Nick Beavis, Salah Ibrahim, Weeratunge Malalasekera
There is significant interest in the gasoline direct-injection engine due to its potential for improvements in fuel consumption but it still remains an area of active research due to a number of challenges including the effect of cycle-by-cycle variations. The current paper presents the use of a 3D-CFD model using both the RANS and LES turbulence modelling approaches, and a Lagrangian DDM to model an early fuel injection event, to evaluate the regimes of combustion in a gasoline direct-injection engine. The velocity fluctuations were investigated as an average value across the cylinder and in the region between the spark plug electrodes. The velocity fluctuations near the spark plug electrodes were seen to be of lower magnitude than the globally averaged fluctuations but exhibited higher levels of cyclic variation due to the influence of the spark plug electrode and the pent-roof geometry on the in-cylinder flow field. Differences in the predicted flame structure due to differences in the predicted velocity fluctuations between RANS and LES modelling approaches were seen as a consequence of the inherently higher dissipation levels present in the RANS methodology. The increased cyclic variation in velocity fluctuations near the spark plug electrodes in the LES predictions suggested significant variation in the relative strength of the in-cylinder turbulence and resultant thickening of the propagating flame front from cycle-to-cycle in this region. Throughout this paper, the numerical results were validated against published experimental data of the same engine geometry under investigation.

Funding

This work was supported by Jaguar Land Rover and the UK-EPSRC grant EP/K014102/1 as part of the jointly funded Programme for Simulation Innovation.

History

School

  • Mechanical, Electrical and Manufacturing Engineering

Published in

Tenth Mediterranean Combustion Symposium

Citation

BEAVIS, N.J., IBRAHIM, S.S. and MALALASEKERA, W., 2017. Numerical evaluation of combustion regimes in a GDI engine. Presented at the Tenth Mediterranean Combustion Symposium (MCS-10), Naples, Italy, 17th-21st September 2017.

Version

AM (Accepted Manuscript)

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/

Acceptance date

16/05/2017

Publication date

2017

Notes

This is a conference paper.

Language

en

Location

Napoli, Italy

Exports

Loughborough Publications

Keywords

Exports