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摘要

Urban Maths: The Betz You Can Do? gave an interesting derivation of wind turbine output from first principles. It does, however, seem to inadvertently overlook one key detail, namely that wind speed varies with height. As stated in paragraph five of the article 'Power increases as the cube of the wind speed, so doubling the wind speed gives an eightfold increase in available power.' Given this sensitivity, we question the validity of the article's conclusion.