- 著者
- 吉住 文太 近藤 靖裕 諸井 隆宏 玉野 真司 森西 洋平
- 出版者
- 一般社団法人 日本機械学会
- 雑誌
- 日本機械学会論文集B編 (ISSN:18848346)
- 巻号頁・発行日
- vol.79, no.806, pp.2003-2018, 2013 (Released:2013-10-25)
- 参考文献数
- 3
- 被引用文献数
- 2 2
The opening delay of a discharge reed valve for compressors caused by the oil film in the clearance between the reed and the valve seat is investigated. The developed simulation method which couples the reed deformation, the gas flow and the oil film flow is applied to simulate delay times on two types of seats with different contact areas. Three models for cavitaion in the oil film are tested; no-cavitation model, the static cavitation model (Reynolds' condition), and the dynamic cavitaton model in which the bubble expansion is directly simulated. The calculaion through the dynamic cavitation model reproduces well experimental results with regard to the delay time and oil film behaviors of cavitation and blow-by (oil film rupture). The result also shows that the growth of cavitation bubbles occupies the change in the oil film volume and prevents the oil film pressure from falling. The rupture mechanism based on the calculation results is that the increase of the oil film thickness directly causes the oil film pressure recovery leading to the blow-by flow, and both cavitation and the smaller contact area promote the growth of the oil film thickness.
- 著者
- 井口 亮 伊藤 基之 玉野 真司 横田 和彦 秋野 詔夫
- 出版者
- 一般社団法人日本機械学会
- 雑誌
- 年次大会講演論文集 : JSME annual meeting
- 巻号頁・発行日
- vol.2004, no.2, pp.319-320, 2004-09-04
The purpose of this research is to develop a new technique for the turbulent drag reduction as the passive control. The pressure loss of three kinds of seal fur (Ribbon, Spotted and Harp seals) and an electret nonwoven fabric surfaces was measured in the channel flow using the water and glycerol-water (40 wt%). The data was compared with those of smooth and riblet surface. The drag reduction could be obtained for all kinds of seal fur surfaces; it was estimated to be 11.5 % on ribbon seal, 9.5 % on spotted seal and 3.5 % on harp seal for glycerol-water, while the drag reduction was not achieved for the electret nonwoven fabric surface.