each element thereby providing a number of adjacent pointwise boundary layer interruptions corresponding to the number of {HEAD ~ blade} like {TAIL ~ members} thereof, 
each element thereby providing a number of adjacent pointwise boundary layer interruptions corresponding to the number of { HEAD ~ blade } like { TAIL ~ members } thereof ,
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH