1321 Multi-component fuel vaporization modelling and its effect on spray development in gasoline direct injection engines S Tonini1*, M Gavaises1†, C Arcoumanis1, A Theodorakakos2, and S Kometani3 1 School of Engineering and Mathematical Sciences, City University, London, UK 2 Fluid Research Co., Athens, Greece 3 Yamaha Motor Company, Japan The manuscript was received on 1 February 2007 and was accepted after revision for publication on 14 June 2007. DOI: 10.1243/09544070JAUTO545 Abstract: A multi-component fuel vaporization model has been developed and implemented into an in-house multi-phase computational fluid dynamics flow solver simulating the flow, spray, and air–fuel mixing processes taking place in gasoline direct injection (GDI) engines. Multi-component fuel properties are modelled assuming a specified composition of pure hydrocarbons. High-pressure and -temperature effects, as well as gas solubility and com- pressibility, are considered. Remote droplet vaporization is initially investigated in order to quantify and validate the most appropriate vaporization model for conditions relevant to those realized with GDI engines. Phenomena related to the fuel injection system and pressure-swirl atomizer flow as well as the subsequent spray development are considered using an one- dimensional fuel injection equipment model predicting the wave dynamics inside the injection system, a Eulerian volume of fluid-based two-phase flow model simulating the liquid film formation process inside the injection hole of the swirl atomizer and a Lagrangian spray model simulating the subsequent spray development, respectively. The computational results are validated against experimental data obtained in an optical engine and include laser Doppler velocimetry measurements of the charge air motion in the absence of spray injection and charge coupled device images of the fuel spray injected during the induction stroke. The results confirm that fuel composition affects the overall fuel spray vaporization rate, but not signifi- cantly relative to other flow and heat transfer processes taking place during the engine operation. Keywords: multi-component fuel vaporization, spray modelling, gasoline direct injection engines 1 INTRODUCTION agreed that the average CO 2 emissions for new cars has to be reduced to 140 g/km by 2008, implying a reduction of fuel consumption of more than 25 per The worldwide concern over global warming and the quantitative relationship between fuel consump- cent from the 1995 baseline, and a more stringent target of CO 2 to 120 g/km by 2012 is under discussion tion and carbon dioxide (CO 2 ) emissions have attracted the attention of automotive manufacturers. [1]. This legislation, combined with the increased customer demand for fuel-efficient vehicles, is lead- The European Commission and the European Auto- motive Manufactures Association (ACEA) in 1998 ing to further research and development of gasoline injection concepts to improve fuel economy. A * Currently at University of Bergamo, Italy number of automotive manufactures have introduced † Corresponding author: School of Engineering and Mathematical gasoline direct injection (GDI) into the European Sciences, City University, London, UK. email: M.Gavaises@ and Japanese markets, since it is proving to offer advantages compared to the port-fuel injection (PFI) city.ac.uk JAUTO545 © IMechE 2007 Proc. IMechE Vol. 221 Part D: J. Automobile Engineering