A fundamental principle of aeronautical engineering has been overturned

Researchers at Tohoku University have overturned an 80-year-old aeronautical engineering principle by demonstrating that microscopic surface roughness (distributed micro-roughness or DMR) can reduce aerodynamic drag by up to 43.6 percent, contrary to the long-held belief that smooth surfaces are essential for minimizing drag. The discovery was made possible using an innovative magnetic levitation wind tunnel system that eliminates measurement interference from support structures, allowing precise testing of subtle surface texture effects.