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