The oscillating flow components are detected with a pair of ultrasonic transducers defining {HEAD ~ an acoustic path} intersecting {TAIL ~ the vortices} 
The oscillating flow components are detected with a pair of ultrasonic transducers defining { HEAD ~ an acoustic path } intersecting { TAIL ~ the vortices }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL