A Study of Initial Process of Liquid Atomization by Using a Semiconductor Laser 2-Focus Velocimeter
| Project/Area Number |
16560151
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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 |
Fluid engineering
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| Research Institution | Nagasaki University |
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Principal Investigator |
UEKI Hironobu Nagasaki University, Department of Engineering, Professor, 工学部, 教授 (30160154)
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| Project Period (FY) |
2004 – 2005
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| Project Status |
Completed (Fiscal Year 2005)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2005: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 2004: ¥2,400,000 (Direct Cost: ¥2,400,000)
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| Keywords | Liquid Atomization / Laser 2-Focus Vel ; ocimeter / Fuel Spray / Droplet Breakup Model / Weber Number / Droplet Velocity / Droplet Szie / Cavitation |
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| Research Abstract |
In order to investigate the initial process of liquid atomization, a smaller probe volume is desired, since each droplet should be identified in high number density droplets. A laser 2-focus velocimeter, L2F, inherently satisfies this requirement, because L2F has a high optical signal to noise ratio and the probe volume is reducible. A L2F, which uses a semiconductor laser as the light source and has a micro-scale probe, was used for the measurement of droplets in a disintegration process. The velocity and size of droplets were measured simultaneously by time-of-flight and time-of-scattering in the probe volume.
1.The measurement accuracy of the L2F developed newly was examined. It is shown that the size of water droplets generated by a humidifier was evaluated as a constant even if the droplet velocity increased 30 times.
2.The measurement of droplet disintegration process near the nozzle orifice, i.e., the initial process of liquid atomization, was conducted in a diesel fuel spray injected into the atmosphere. It is shown that large and high velocity droplets disintegrate in the spray core.
3.Enhanced TAB model, one of droplet disintegration model, was verified by the L2F measurement result. It is shown that the enhanced TAB model can simulate the droplet disintegration process in the spray core if the droplet size after disintegration is suitably estimated.
As the developed L2F can measure the velocity and size of droplets when a droplet's interval is longer than the distance between two foci, L2F can not measure a liquid column. However, when invalid data is obtained by the L2F, existence of a liquid column is suggested. The measurement of a liquid column by the L2F is a future subject.
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Report
(3 results)
Research Products
(21 results)
