2007 Fiscal Year Final Research Report Summary
A Study on a Droplet Combustion Behavior in a Simulated Microgravity condition by Electric Fields
| Project/Area Number |
18560756
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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 |
Aerospace engineering
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| Research Institution | The University of Tokyo |
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Principal Investigator |
TSUE Mitsuhiro The University of Tokyo, Graduate School of Engineering, Professor (50227360)
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| Co-Investigator(Kenkyū-buntansha) |
KONO Michikata National Institute for Academic Degrees and University Evaluation, 学位授与機構評価研究部, Professor (60011194)
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| Project Period (FY) |
2006 – 2007
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| Keywords | Microgravity / Droplet Combustion / Soot Particle / Electric Field / Ion Wind / PTV / Natural Convection |
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| Research Abstract |
Both the electric force working on flames and the buoyancy are body fore, so there is a possibility to control the buoyancy with applying the electric field. It is important to discuss the body force in the flame because it induces the convective flow around flames. In this circumstance, combustion behavior of single droplets in vertical direct current (DC) electric fields was investigated. Ethanol, n-octane, and toluene were used as fuels, and the flame shape and the burning rate constant were measured. The spacing between the electrodes is 50mm and the applied voltage ranged between -4kV and 6kV as the bottom electrode is ground. When the direction of the electric field is opposite to the buoyancy direction, the applied voltage exists that make the flame symmetry in the vertical direction, and the burning rate constants have local minima for ethanol and n-octane at the voltage. However, the minimum burning rate constants are larger than those under microgravity. This means that the micro-buoyancy condition can be accomplished by the electric fields, but it is not no-buoyancy. When the direction of the electric filed is same direction of the buoyancy, there exist some experimental results which cannot be explained by the assumption that electric field induces the body force only through the positive ions. This suggests that the additional body force is induced by the negative ions. The effects of the movement of negative charged soot particle on the combustion behavior are also discussed for sooty flame of toluene.
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