著者
青木 繁光 小垣 哲也 浅沼 則道 高野 裕文
出版者
一般社団法人 日本エネルギー学会
雑誌
日本エネルギー学会機関誌えねるみくす (ISSN:24323586)
巻号頁・発行日
vol.97, no.2, pp.164-170, 2018-03-20 (Released:2018-03-30)
参考文献数
3

北太平洋上の強風海域において風力を利用して帆走しながら水中のロータ(水車)によって発電機を駆動し,海水から電気分解して得られた水素を貯蔵して自力で持ち帰る大型帆船を提案する。1ユニットあたり100メガワットを超えるシステムの開発が可能であり,水素キャリアとしてCO2を用いたケースではCO2フリー水素を供給しながらCO2リザーバとしての機能を有する,すなわち「資源・環境問題の同時解決」(1991年;向坊東大名誉教授)が可能となる。
著者
大竹 悠介 近藤 勝俊 藤田 恵美 小垣 哲也 櫻井 健一
出版者
一般社団法人 日本風力エネルギー学会
雑誌
風力エネルギー学会 論文集 (ISSN:24363952)
巻号頁・発行日
vol.45, no.2, pp.23-30, 2021 (Released:2021-12-15)

A downwind turbine whose rotor surface is located on the leeward side with respect to the tower is expected to operate with high efficiency in up-flow wind. In addition, it is expected that a large amount of up-flow wind will be shown in mountainous areas that are common in Japan. Therefore, the wind conditions around the downwind turbine installed in the mountainous area were measured by Doppler LiDAR, and the wind turbine performance in the up-flow wind was evaluated. As a result, it was confirmed that the power of the wind turbine tends to improve as the flow inclination angle becomes larger and closer to the wind turbine tilt angle.
著者
嶋田 進 大澤 輝夫 往岸 達也 菊島 義弘 小垣 哲也 川口 浩二 中村 聡志
出版者
一般社団法人 日本風力エネルギー学会
雑誌
風力エネルギー (ISSN:03876217)
巻号頁・発行日
vol.38, no.2, pp.A_29-A_35, 2014

Vertical wind speed profiles near the coast were observed using a Doppler Light Detection and Ranging (LIDAR) system at the Hazaki Oceanographical Research Station (HORS) from September 17 to 26, 2013. In order to investigate the impact of atmospheric stability, wind profiles observed at HORS were compared with a log profile model (theoretical wind profile model), which did not consider atmospheric stability. The wind shear was smaller in the observed profiles when the wind came from sea to land, and larger when it came from land to sea. It was also found that the wind profiles included an obvious diurnal cycle when the wind came from land to sea. The results for this study indicate that atmospheric stability is a significant factor when determining the coastal wind profiles, not only when the wind comes from sea sectors, but also from land sectors.
著者
小垣 哲也 小林 敏雄 谷口 伸行
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:03875016)
巻号頁・発行日
vol.65, no.633, pp.1559-1567, 1999-05-25 (Released:2008-03-28)
参考文献数
15
被引用文献数
3 2

In order to conduct direct numerical simulation (DNS) or large eddy simulation (LES) of turbulent flows in complicated flow geometry, accurate finite difference methods are needed in generalized curvilinear coordinate system. Recently, it was shown that the analytical conservation properties of the set of basic equations are needed to be satisfied properly even in discretized basic equations in order to obtain accurate and stable solutions in simulations of incompressible turbulent flow using finite difference method. The basic equations treated here are the continuity equation, the Navier-Stokes equation and the transport equations of the square values of velocity components and the kinetic energy. In this paper, finite difference schemes in generalized curvilinear coordinate system that are suitable for simulations of incompressible turbulent flow are constructed from relatively simple extension of the proper finite difference schemes derived in equidistant Cartesian coordinate system. The extension of finite difference scheme into generalized curvilinear coordinate system is based on the fact that the analytical conservation properties of the coordinate transformed basic equations for incompressible viscous flows are identical with that in Cartesian coordinates.