Boeing is investigating the use of oscillating jets of air at certain locations on an aircraft wing to significantly reduce drag and consequently boost speed or fuel economy for high speed cruise, including transonic or supersonic regimes.

Analysis presented as supporting material for a US patent titled “Dynamic bumps for drag reduction at transonic-supersonic speeds” (application number 20090084906) shows overall mean drag reductions as high as 7.3% relative to a normally configured wing.

At transonic or higher speeds, air flowing over a swept wing is accelerated causing drag producing a “normal” shockwave that extends upward from the rear portions of the aerofoil. The “dynamic bumps” system proposes a grid of oscillating jets, some that suck air and some that expel air, to create a recirculation pattern with magnitude and frequency that acts to weaken the normal shock wave by creating an oblique wave that acts to reduce aerofoil drag.

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