| Project/Area Number |
10650199
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Thermal engineering
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| Research Institution | The University of Tokyo |
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Principal Investigator |
AZETSU Akihiko Graduate School of Engineering, The University of Tokyo, Associate Professor, 大学院・工学系研究科, 助教授 (80184175)
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| Project Period (FY) |
1998 – 1999
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| Project Status |
Completed (Fiscal Year 1999)
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| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 1999: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 1998: ¥2,400,000 (Direct Cost: ¥2,400,000)
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| Keywords | Intermittent Spray Combustion / Fuel Injection / Fuel Injection Rate Shaping / Intermittent Spray / Ignition / Combustion Period / Spray Angle / Piezoelectric Actuator / 燃焼期間 / 液柱 / 燃焼噴射 / 主燃焼 / 二色法 |
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| Research Abstract |
By developing and using an original electronically controllable fuel injection system, effect of injection rate shaping on intermittent spray and combustion was studied.
(1) Development of Fuel Injection System for Variable Injection Rate Shaping : In our system, the arbitrary injection rate shaping was obtained by controlling the movement of nozzle needle directly with piezoelectric actuator. By using a high power actuator, injection pressure of up to 100MPa was achieved in this study.
(2) Effect in Single Injection : At the same conditions of injection period, peak injection rate and total amount of fuel injected, the spray with triangular injection rate shaping and different slope of injection rate rise for some injection pressures was examined. It was found that the slope of injection rate rise made great influences on the temporal evolution of the spray, the ignition and main combustion of the spray flame. Higher injection pressure enhanced the growth of spray and promoted the combustion especially at initial stage. These tendencies result in a shorter combustion period for all injection rate shaping. From the viewpoint of shorter combustion period, the optimum fuel injection rate shaping changes with injection pressures.
(3) Effect in Two Stage Injection : It was made clear that the injection interval gives a large effect on the spray evolution of 2nd stage injection and overall combustion. These effects change with the injection rate shaping of 2nd stage injection.
(4) Effect of Periodical Fluctuation of Injection Rate : Effect of periodical fluctuation of injection rate with relatively higher frequency was examined. From the visualized experiments, it was made clear that the spray dispersion becomes wider at some specified frequencies. In the spray with periodical fluctuation, a large cloud of fuel droplets was ejected from the dense liquid core and the length of liquid core becomes very short at above mentioned frequencies.
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