2001 Fiscal Year Final Research Report Summary
Instability af the Oil Film of Thrust Bearings
| Project/Area Number |
12650136
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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 |
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 Univ. Faculty of Eng. Professor, 工学部, 教授 (30008867)
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| Co-Investigator(Kenkyū-buntansha) |
YAMAMOTO Hiroshi Saitama Univ. Faculty of Eng. Associate Professor, 工学部, 助教授 (20220494)
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| Project Period (FY) |
2000 – 2001
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| Keywords | hydro-dynamic lubrication / lubrication / transition / turbulence / instability of oil film / oil film bearing / thrust bearing / transition from laminar to turbulence |
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| Research Abstract |
Experimental investigations of instability in the fluid film of thrust bearings are presented. Flow between a stational and a rotational disk of 80 mm diameter are used as a model of fluid film of thrust bearings. The gap between two disks is 0.5 mm. Water is used as a working fluid. In order to visualize the flow, two types of fine particles are used. One is the powder of barium sulfate of 2〜5μm diameter and the other is Monodisperse Fluorescent Polymer Microspheres of 0.9 μm diameter. In case of using barium sulfate powder for visualization, under appropriate lighting, the flows are observed and taken a photo. Then, to avoid the diffused reflections from the disk surfaces, Fluorescent Microspheres are used as additives for visualization and lightened by ultraviolet rays. As a result, we can get following conclusions :
(1) Photographs show the three types of instability patterns are observed. The first one is the spiral vortex generating in high Reynold's number region and the vortex lines are nearly concentric. This phenomena is called type I instability. The second one is a series of wave like pattern generating in the middle Reynold's number region and called viscous instability or type II instability. This pattern is on the fixed disk and exists in the half region of the gap. The third one is cross pattern
(2) We can avoid the diffused reflections from the disks by using the Monodisperse Fluorescent Polymer Microspheres and get clear photographs of the cross sections of the gap
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Research Products
(4 results)
