JFET_V5_N2_RP7 P. Manoj Kumar V. Pandurangadu Journal on Future Engineering and Technology 2230 – 7184 5 2 48 54 Spray, Orientation, Diesel Engine In direct injection (DI) diesel engines the fuel spray characteristics have high influence on engine performance as well as exhaust gas emissions. The fuel spray orientation plays very important role in fuel air mixing. A single cylinder four stroke DI diesel engine with fuel injector having multi-hole nozzle injector is considered for the analysis and a computational fluid dynamics (CFD) code, STAR-CD is used for the simulation. In the present study, various fuel spray orientations are considered for the analysis. It is shown that there is an optimal orientation for the fuel spray and the wall wetting area influences on the emission formations. Results are reported for distribution of fuel spray for different spray orientations and discussions are made with the profiles of pressure, temperature, number of droplet parcels, turbulent kinetic energy (TKE)., and exhaust gas emissions. November 2009 - January 2010 Copyright © 2010 i-manager publications. All rights reserved. i-manager Publications http://www.imanagerpublications.com/Article.aspx?ArticleId=1098