著者

小林 文明 鈴木 菊男 菅原 広史 前田 直樹 中藤 誠二

出版者

一般社団法人 日本風工学会

雑誌

日本風工学会論文集 (ISSN:13493507)

巻号頁・発行日

vol.32, no.1, pp.21-28, 2007 (Released:2007-08-24)

参考文献数

17

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The detailed structure of a gustfront was revealed with Doppler radar, Doppler sodar, weather station and video cameras at Yokosuka observation site, Japan. The gustfront was accompanied with a downburst from bow echo of developing thunderstorm. Two gusts occurred at the passage of gustfront. First gust was observed about 2 km behind the gustfront. Second gust occurred about 5 km behind of the first gust and maximum wind speed of the second gust was larger than that of the first gust. The vertical circulation of the gustfront had about 5 km in horizontal scale and 500 m in vertical and made "arc cloud" , which had 200m of cloud base and 500m of cloud top in height. Strong wind cores (> 25 m/s) existed between 30 m and 500 m in height at the front of the circulation. Two gust winds, which were observed at the surface, were well corresponded with the strong wind core near the surface and updraft region of the circulations. Vertical distribution of the wind speed changed remarkably for 5 minutes in the vertical circulations.

著者

中藤 誠二

出版者

一般社団法人 日本風工学会

雑誌

日本風工学会年次研究発表会・梗概集

巻号頁・発行日

vol.2013, pp.169-170, 2013

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パンチングメタルを対象に,風洞実験において風速を変化させて発生する空力音を測定し,音圧レベルや周波数特性を調べた.まず,対象とする空力音を発生させるために,模型支持装置の工夫を行ったのち,迎角80度の場合について,風速12.5m/sまでの範囲で空力音の測定を行った.対象とした3ケースでは,孔配列によるピークの基本周波数の違いは小さく,風速に比例した1kHz前後の比較的高い周波数のピークが見られ,発生周波数は孔径に依存しているものと考えられる.