First reported by Hacker News
New Research Overturns Long-Held Belief That Smoother Surfaces Always Reduce Aerodynamic Drag
Study Overturns Long-Held Aeronautical Principle: Smoother Surfaces Don't Always Reduce Drag
By
Ritsuko Kawai
8h ago· 7 min readenNews
90/100
Golden Brown
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Summary
A new discovery challenges the long-held aeronautical principle that smoother surfaces always reduce aerodynamic drag. The article explains how the boundary layer (laminar vs. turbulent flow) affects drag, and reveals that under certain high-speed conditions, intentionally roughened surfaces can actually improve performance by manipulating the transition between laminar and turbulent flow. This overturns a fundamental assumption in aeronautical engineering with implications for aircraft, automobiles, and high-speed trains.
Key quotes
· 3 pulledAerodynamic drag is a major 'barrier' in high-speed airplanes, automobiles, and bullet trains.
The longer the air stays in the laminar-flow state with low friction, the smaller the air resistance becomes, but as the air speed increases...
It's long been accepted that the smoother the surface, the lower the aerodynamic drag. That turns out not always to be the case.
It’s long been accepted that the smoother the surface, the lower the aerodynamic drag. That turns out not always to be the case.
