1993 Fiscal Year Final Research Report Summary
ON THE INSTABILITY OF FLUID FILM OF THRUST BEARINGS
| Project/Area Number |
04452132
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
設計工学・機械要素・トライボロジー
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| Research Institution | SAITAMA UNIVERSITY |
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Principal Investigator |
HARADA Masami SAITAMA UNIVERSITY, MECHANICAL ENGINEERING, PROFESSOR, 工学部, 教授 (30008867)
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| Co-Investigator(Kenkyū-buntansha) |
MIYAJI Ryutaro SAITAMA UNIVERSITY, MECHANICAL ENGINEERING, RESEARCH ASSISTANT, 工学部, 助手 (00008872)
SASAJIMA Kazuuki SAITAMA UNIVERSITY, MECHANICAL ENGINEERING, ASSOCIATE PROFESSOR, 工学部, 助教授 (80170702)
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| Project Period (FY) |
1992 – 1993
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| Keywords | Lubrication / Turbulent lubrication / Rotating disks / Instability / Critical Reynolds number / Transition |
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| Research Abstract |
A phenomena of instbility of fluid film between rotating disk and stationary one is investigated. Visualization techniques using BaSO_4 powder and alminum one show streaks and special patterns in the fluid film, denoting a vortex system generated in the region of flow upstream of fully developed turbulent flow. And frictional torque of the disk are also measured. These results read us following conclusions.
(1) Critical Rynolds number Reh(=omegarh/nu, r : radius, omega : rotational speed, h : theckness of the fluid film, nu : kinematic viscosity) for the instability depend on 1Ek(=omegah^2nu) only.
(2) In the region of 1/Ek (〕SY.ltoreq.〔) 6, Reh tends to 1.20x10^3.
(3) Calculated results in wide gaps agree well with the present one.
(4) When the instability occurs in the outer edge of a disk, Frictional torque abruptly increase.
(5) In the lower Reynolds number region, cross striped patterns are found.
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