On the relative roles of fuel spray kinetic energy and engine speed in determining mixing rates in D.I. diesel engines
- University College Dublin (Ireland). Dept. of Mechanical Engineering
This paper describes an attempt to separate out and to quantify the relative importance of fuel injection characteristics and in-cylinder air motion as factors influencing the rate of fuel-air mixing and of combustion in high-speed Direct Injection (D.I.) diesel engines, where bulk swirling air motion is absent. Tests on a 121 mm bore x 139 mm stroke, 1.6 liter, single-cylinder engine at constant engine speed reveal substantially shorter fuel-air mixing times as the mean fuel injection kinetic energy (M.I.K.E.) is increased. Also, tests at constant injection kinetic energy but with varying engine speed (involving different fuel injection system builds at each speed) show that fuel-air mixing times are reduced at higher engine speeds. From these trends it is concluded that, while injection kinetic energy is the dominant factor in determining fuel-air mixing rates in D.I. diesels, small-scale turbulent air motions, the intensity and structure of which are related to engine speed, also exert an important influence on the mixing rate.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 483738
- Journal Information:
- Journal of Engineering for Gas Turbines and Power, Journal Name: Journal of Engineering for Gas Turbines and Power Journal Issue: 1 Vol. 119; ISSN JETPEZ; ISSN 0742-4795
- Country of Publication:
- United States
- Language:
- English
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