each bladed interrupter element comprising {TAIL ~ a common core} and at least three blade like {HEAD ~ members} extending mutually outwardly from the common core so as to separately touch or nearly touch the said apparatus surface or surfaces immediately adjacent to the respective element, each blade like member being of at least approximately spherical segment profile in side elevation so that the portion thereof most closely adjacent to the respective apparatus surface protrudes into the said fluid flow boundary layer for pointwise interruption thereof 
each bladed interrupter element comprising { TAIL ~ a common core } and at least three blade like { HEAD ~ members } extending mutually outwardly from the common core so as to separately touch or nearly touch the said apparatus surface or surfaces immediately adjacent to the respective element , each blade like member being of at least approximately spherical segment profile in side elevation so that the portion thereof most closely adjacent to the respective apparatus surface protrudes into the said fluid flow boundary layer for pointwise interruption thereof
OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH