The elements are spaced longitudinally from one another the distance required to provide wake interference flow of {HEAD ~ the fluid}, wherein the vortex upstream of one element cooperates with the vortex downstream of the next element in {TAIL ~ the fluid path} 
The elements are spaced longitudinally from one another the distance required to provide wake interference flow of { HEAD ~ the fluid } , wherein the vortex upstream of one element cooperates with the vortex downstream of the next element in { TAIL ~ the fluid path }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL