Yoshihide Tominaga

建築と風の問題には，建物に作用する風荷重や風振動のような構造的な問題から，ビル風や都市内の熱や汚染物質の拡散のような環境的な問題まで，様々なものがある．本稿では，建築分野におけるCFDと風洞技術の連携の現状と課題について概説する．連携の形態としては，①CFDの検証（Validation）のために風洞実験結果の使用，②CFDのモデルの高度化・改良のための風洞実験の利用，③相互のスケールの補完，④風洞実験を効率化・高度化するためのCFDの利用，の４つが考えられる．それぞれの方法の特徴を理解した上で，相互を補完的に利用していくことが今後も重要である．

The accuracy of wind power generation predicted by computational fluid dynamics (CFD) simulations combined with meteorological wind data was validated based on comparisons with directly measured data for a small vertical axis wind turbine system installed on a university campus. The CFD simulations were performed in accordance with established guidelines and frameworks for the prediction of urban wind environments. At the rooftop location, where small wind turbines are typically installed, the deviations in wind velocity from the measurements are quite large. However, in the present study, the prediction accuracy for the wind turbine site, which was 4 m above the ground, was acceptable. The total power generation estimated using the assumed power curve based on the rated output of the turbine was 56% larger than that directly measured by the power generator. However, using the power curves obtained from the measurements, the total power generation could be predicted with a high degree of accuracy and with an error of approximately 3%. It is suggested that not only the accuracy of the wind velocity but also that of the power curve is very important because they are directly related to that of the predicted power generation.