Tohoku University researchers reduced drag by up to 43.6% in wind-tunnel tests of Distributed Micro-Roughness, a patterned surface texture. The team says the texture suppresses Tollmien-Schlichting waves, delaying the shift from smooth to turbulent airflow.
The tests used models suspended without struts in a magnetic levitation wind tunnel. The result has not been validated on full-size aircraft, and researchers still need a way to keep the texture from clogging with dirt, bugs and other residue.
