2002 Fiscal Year Final Research Report Summary
Effect of Turbulent Flow Field on Flame Developing in Fuel Gradient Field in a Constant-Volume Vessel
| Project/Area Number |
13650222
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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 | OKAYAMA UNIVERSITY |
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Principal Investigator |
TOMITA Eiji Okayama University, Graduate School of Natural Science and Technology, Professor, 大学院・自然科学研究科, 教授 (80155556)
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| Co-Investigator(Kenkyū-buntansha) |
YOSHIYAMA Sadami Okayama University, Graduate School of Natural Science and Technology, Lecturer, 大学院・自然科学研究科, 講師 (80210780)
KAWAHARA Nobuyuki Okayama University, Graduate School of Natural Science and Technology, Research Associate, 大学院・自然科学研究科, 助手 (30314652)
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| Project Period (FY) |
2001 – 2002
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| Keywords | Turbulent Premixed Flame / Combustion / Laser Diagnostics / Stratified Charge Combustion / Gradient of Fuel Concentration |
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| Research Abstract |
In direct injection spark-ignition engine, thermal efficiency can increase about 20-30% in low load, leading to decrease in carbon dioxide. However, die phenomena are very complicated and difficult in actual engines. Therefore, in order to investigate each phenomenon fundamentally, it is necessary to make the fields easy to analyze. In this study, a swirl flow was produced in a constant-volume vessel of disk type and a flame developed axisymmetrically by igniting at the center with supplying fuel of propane at the center of the combustion chamber. Experiments were done in various turbulent flow and concentration fields. Turbulent flow was measured with a laser Doppler anemometer and fuel concentration field was measured with a laser induced fluorescence method. A high-speed video camera was used to capture the flame development Hydrocarbon after the combustion was measured with absorption method using a laser of 3.39 micrometer wavelength.
Main results for overall combustion are as follows: (1) In this experiment, both turbulent flow and concentration fields were changed. However, it was found that average fuel concentration is almost the same but the turbulent floe is different Therefore, only the effect of turbulence intensity was investigated. (2) The combustion efficiency was over 97% when overall equivalence ratio is larger man 0.7 while the combustion efficiency presented lower value of 0.3 in some cases at lower equivalence ratio less than 0.7. (3) When richer fuel existed near the center of The combustion chamber, it was observed that the flame developed with a lot of luminous parts in it As for initial combustion, main result is summarized as follows: (4) The mixture can ignite and flame propagates even outside the flammable limits because inhomogeneous mixture includes a lot of richer and leaner parts that are within the flammable limits including stoichiometric condition.
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Research Products
(10 results)
