巻号一覧
1987 巻 (1987)
- 33 号 p. 1-
- 32 号 p. 1-
- 31 号 p. 1-
前身誌
1987 巻, 33 号
選択された号の論文の4件中1～4を表示しています
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村上 周三, 赤林 伸一1987 年 1987 巻 33 号 p. 1-8
発行日: 1987/09/30
公開日: 2010/09/28
ジャーナル フリーExperimental Study on Natural Ventilation of Dwellings Estimation of Air Change Rates by Tracer Gas Method with Wind Tunnel Experiment
The characteristics of wind induced natural ventilation of dwellings are analyzed by wind tunnel experiment. The amount of ventilation air introduced into a house are measured by tracer gas method. The results are as follows.
(1) To clearify the amount of ventilation air into the house, it is valid that to inject tracer gas (C2H4) at the windward opening and to measure the stationary concentration of tracer gas at the leeward opening.
(2) Air change rates are nearly constant when wind directon changes from +30° to -30° in a vertical line to the opening.
(3) It is an obstacle for natural ventilation to attach anything at the windwardopenings.抄録全体を表示PDF形式でダウンロード (1428K) -
Charles W. KNISELY1987 年 1987 巻 33 号 p. 9-43
発行日: 1987/09/30
公開日: 2010/09/28
ジャーナル フリーVortex-shedding from bluff bodies, such as buildings and bridge decks, with rectangular cross sections often produces significant unsteady loading of these structures. These rectangular cross section structures are characterized by two shear layers separating from fixed separation points at the two upstream corners. The present paper explores the relationship between vortex shedding and the instability of these free shear layers separating from the upstream corners of idealized two-dimensional rectangular structures. Further, possible feedback mechanisms for the enhancement of the shear layer instability are critically examined. The reduced velocity regions over which classical vortex shedding, heaving vibrations and torsional oscillations are normally expected are shown to be at least an order of magnitude above the crudely estimated reduced velocity region corresponding to shear layer instability. Thus, if shear layer instability plays any significant role in the sustenance of heaving or torsional flow-induced vibrations, a mechanism which overcomes this frequency mismatch must exist. One such hypothetical mechanism, involving an inviscid oscillation of the time mean separation bubble and the “collective interaction”(Ho and Huang [1982]) of shear layer vortices, is proposed.抄録全体を表示PDF形式でダウンロード (5219K) -
吉田 正昭, 中村 修, 横谷 恵二, 片桐 純治1987 年 1987 巻 33 号 p. 45-50
発行日: 1987/09/30
公開日: 2010/09/28
ジャーナル フリーWe made the closed-circuit type boundary layer wind tunnel for the experiment ofwind effect on and around buildings. The characteristics of this tunnel are followed.
1) The width of the test section is 3.1 m, the height is 2.0 m, and, the length is 15 m. And a 2.5 m diameter turn-table can set in the tunnel.
2) This tunnel has few contracted and diffused section, and has no nets andhoneycombs. For that reason, the power of motor is 30 KW, but the maximum wind speed is 22 m/s.
3) The deviation of wind speed. at the test section is 3-4 %, and the curbulent intensity at the center of this section is about 1.5%.抄録全体を表示PDF形式でダウンロード (1452K) -
Research Department Materials and Structures. German Aerospace Research Establishment, Göttingen, West Germany田村 幸雄, 持田 灯1987 年 1987 巻 33 号 p. 113-116
発行日: 1987/09/30
公開日: 2010/09/28
ジャーナル フリーPDF形式でダウンロード (936K)
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