seen to include a surface generally designated 12 constituted as plural ribs 14 the ribs 14 have a 34 v shaped 34 cross section defined by constitutive confronting riblets 16 18 in alternating relation the ribs 14 are elongated along the direction of flow the constitutive riblets 16 18 thereof preferably define a forty five 45 degree spacial angle therebetween in the presently preferred embodiment the riblets 16 18 of the v shaped ribs 14 of the structure 12 are spaced apart a distance designated by arrows 20 of one hundred 100 microns and are upstanding a distance designated 22 again of one hundred 100 microns any suitable structure 12 such as the 34 microgrooves 34 commercially available from the 3 m company may be employed whichever structure 12 is employed it is only important that the dimensions thereof be selected to lie within the turbulent boundary layer each of the constitutive confronting vanes 16 18 of the several v shaped ribs 14 of the structure 12 are respectively provided with an electrically conductive electrode generally designated 24 such as platinum or silver and a magnet generally designated 26 the electrodes 24 thereof extend along the direction of elongation of each of the vanes and may be provided as a thin film preferably twenty 20 microns thick by sputter deposition and thin film deposition chemical vapor deposition among other techniques well known to those skilled in the art the magnets 26 thereof likewise extend along each of the vanes and may be provided as a thin film preferably twenty 20 microns thick of nd b fe or other suitable permanent magnetic material by these same techniques the.