Comments by "John Berry" (@user-ud6ui7zt3r) on "Genius Inventions: Technical Marvels That Will Shape Tomorrow | Full Series | FD Engineering" video.

I thought that serrated blade or serrated wing edges had long ago been attributed to detailed analysis of owl feathers. Applications of the OWL feather analysis, which was performed long ago, include serrated edges on cooling fan blades (used in computer power supplies.) The serrations are said to make for quieter cooling fan operation. If I am not mistaken, Rolls Royce turbine blades, found in Rolls Royce jet engines, also exhibit deliberate serrations. Even Donald Trump attests to the fact that Rolls Royce jet engines are quieter than the jet engines made by other companies.
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