Study on Flow Characteristics of Cryogenic Hybrid Journal Bearings

2015 Fiscal Year Final Research Report

• Project/Area Number: 25420128
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Fluid engineering
• Research Institution: Ishinomaki Senshu University
• Principal Investigator: Oike Mamoru 石巻専修大学, 理工学部, 教授 (70292282)
• Co-Investigator(Kenkyū-buntansha): TAKADA Satoshi 国立研究開発法人宇宙航空研究開発機構, 研究開発部門, 研究員 (30358569)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 流体工学 / 航空宇宙工学 / トライボロジー / 混相流 / 極低温流体

Outline of Final Research Achievements

The flow visualization experiment in the clearance between the clear floating-ring (CFR) and the rotating journal was carried out using liquid nitrogen as the working fluid in order to clarify effect of the recess geometry on the flow characteristics of the cryogenic hybrid journal bearings (HJB).
The dependence of the flow characteristics on the rotational speed was confirmed to be affected by the sweepback angle of the recess leading edge. The results demonstrated that the pumping effect of the recess with a negative sweepback angle is stronger than that of the positive angle. However, the strong pumping effect may produce a large pressure fluctuation in the circumferential direction, which seems to excite journal vibration for the HJB. Furthermore, comparison between the experiment and the calculation indicates that the recess geometry strongly affects the cavitation area ratio, and weekly influences the flow coefficient because of the choked flow at the clearance outlet.

Free Research Field

流体工学とトライボロジーの融合分野