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Analysis of relation between mixture formation during ignition delay period and burning process in diesel combustion

Khalid , Amir and Tomoaki , Yatsufusa and Takayuki , Miyamoto and Jun , Kawakami and Yoshiyuki , Kidoguchi (2009) Analysis of relation between mixture formation during ignition delay period and burning process in diesel combustion. In: 15th Small Engine Technology Conference (SETC 2009), 3rd-5th November 2009, Penang, Malaysia.


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Many technologies for reducing exhaust emissions of wide variety of diesel engines from small size to large size ones have been considered with the improvement throughout the combustion process. To reduce emissions, mixing of fuel and air is still important phenomena. Purpose of this study is to clarify the relation between mixture formation during the ignition delay period and burning process in diesel combustion that strongly affects the exhaust emissions. In this study, a rapid compression machine was used to simulate actual phenomenon inside the combustion chamber with changing ambient density. In addition, swirl velocity and injection pressure were changed as experimental parameters to improve mixture formation at high ambient density. This study constructed schlieren photography system with a high-speed digital video camera to investigate the detail behavior of mixture formation during ignition delay period. This method can capture spray evaporation, spray interference and mixture formation process clearly. Ignition process and flame development were investigated by direct photography method using a light sensitive high-speed color digital video camera. The sensitive camera can capture flame development clearly with the mixture of dark and bright flames. Moreover, the mechanism and behavior of flame pattern were analyzed by newly developed image analysis technique. Flame images reveals that spray ignition occurs with dark flame between sprays at the middle and downstream of the spray where combustible mixture is first formed; then bright flame appears near the centerline of each spray where fuel is continuously injected to rich and high temperature atmosphere. Increasing ambient density restrains spray tip penetration, resulting that mixture is only formed at the center region of the combustion chamber. It is necessary for high ambient density condition to improve mixture formation. High-pressure injection is most effective in improvement of mixture formation under condition of high ambient density.

Item Type: Conference or Workshop Item (Paper)
Uncontrolled Keywords: mixture formation; diesel combustion; ignition delay; ignition process; spray; Rapid Compression Machine; flame Pattern, Image analysis, High boost pressure,image analysis technique, optical setup, injection pressure, swirl velocity
Subjects: T Technology > TJ Mechanical engineering and machinery > TJ751-805 Miscellaneous motors and engines
Divisions: Faculty of Mechanical and Manufacturing Engineering > Department of Plant and Automotive Engineering
Depositing User: Dr. Amir Khalid
Date Deposited: 03 Jan 2012 01:04
Last Modified: 03 Jan 2012 01:04
URI: http://eprints.uthm.edu.my/id/eprint/2202
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