The effect of orifice diameter in constant volume chamber to spray characteristics in diesel engine using computational fluid dynamic

¹ Centre of Energy and Industrial Environment, Universiti Tun Hussein Onn Malaysia, 86400 Parit Raja, Batu Pahat, Johor, Malaysia
² Faculty of Mechanical Engineering, Universiti Tun Hseein Onn Malaysia, 86400 Parit Raja, Batu Pahat, Johor, Malaysia

^* Corresponding author: adiba_rhaodah@yahoo.com

Abstract

Mixture formation of the ignition process is a crucial part in diesel combustion as it affects the combustion process and exhaust emission. The main focus of this study is to investigate the effects of spray characteristic to the fuel spray in a chamber using Computational Fluid Dynamics (CFD) simulation. However, simulations are done with the discrete phase of injection taken from the outlet of the nozzle hole to spray chamber. The details behavior of spray penetration and spray breakup length were visualized using Computational Fluid Dynamics. This simulation was done in different nozzle diameters 0.12 mm and 0.2 mm performed at a single ambient pressure of 4 MPa, the ambient temperature of 500 K and 700 K with different injection pressure 40 MPa, 70 MPa and 140 MPa. Results showed that the droplet diameter is influenced by high pressure to become smaller, and the penetration length also longer with high injection pressure applied. Besides, smaller orifice diameter gives a shorter length of the breakup. It is necessary to put afford on orifice diameter and ambient temperature conditions in order to improve the formation of spray.