Method and apparatus for reducing turbulent drag

A method of controlling a boundary layer, comprising:

• arranging on a surface of an object sequentially in a stream-wise direction a plurality of magnets with poles of opposite polarity and electrodes interposed between respective pairs of the magnets, the electrodes forming a two-dimensional pattern with respective rows substantially aligned in a span-wise direction and a stream-wise direction,
• exposing the surface of the object to a medium flowing over said surface in the stream-wise direction, and
• applying an electric bias signal to the electrodes in a stream-wise row so that the electric bias signals applied to neighboring electrodes in said stream-wise row have an opposite potential,
• wherein the electric bias signals applied to the electrodes in span-wise rows are phase-shifted with respect to one another and wherein at least one stream-wise row with unbiased electrodes is inserted between those stream-wise rows that have adjacent electrodes of opposite polarity located in the same row in the span-wise direction.

A boundary layer control system comprising:

• an object having at least one surface exposed to a medium flowing over the surface in a stream-wise direction,
• a plurality of magnets having magnetic poles alternating in the stream-wise direction arranged on the surface, and
• a plurality of electrodes disposed between respective pairs of the alternating magnetic poles arranged on the surface and capable of exciting a traveling wave force field in a span-wise direction substantially parallel to the surface and perpendicular to the stream-wise direction, with a first component of the traveling wave force field in the span-wise direction being substantially greater than a second component of the traveling wave force field substantially perpendicular to the span-wise direction,
• wherein the electrodes have a peripheral contour adapted to homogenize charge distribution on the electrodes.