1988 Fiscal Year Final Research Report Summary
Laminar-Turbulent Transition in a Free Liquid Film Flow and its Application to the Atomization
| Project/Area Number |
61550135
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Fluid engineering
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| Research Institution | Osaka City University |
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Principal Investigator |
AZUMA Tsuneo Associate Professor of Mechanical Engineering, Osaka City University, 工学部, 助教授 (40047329)
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| Project Period (FY) |
1986 – 1988
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| Keywords | Boundary layer / Laminar-turbulent transition / Liquid film flow / Rotating disk / Atomization / LDV measurement / 流れの安定性 |
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| Research Abstract |
1. The laminar-turbulent transition in the radial flow of a free liquid film is studied experimentally and theoretically. The flow is generated by making a thin radial liquid film along a horizontally placed circular disk and letting it flow out into the atmosphere. The transition mechanism is observed using a stroboscope. The velocity distributions in a thin free liquid film having a thickness of about 0.2 mm are measured by LDV. The phenomena of the transition is investigated by means of the linear stability theory. As a result, the transition is caused on the nonuniformity of the vorticity distribution inside the liquid film. 2. The laminar-turbulent transition in the radial liquid film flow on a rotating disk is studied experimentally. The flow is generated by letting water discharge from a cylindrical opening between a horizontally placed rotating disk and a circular nozzle into the atmosphere along the upper surface of the disk. The high speed photographes of the process of the transition show that, while the rotation of disk suppresses the transition as long as the circumferencial velocity is relatively small to the radial velocity, it promotes the transition when the circumferencial velocity becomes large.
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