Compared with {TAIL ~ a flow} without {HEAD ~ a radius}, the backflow bubble 50 is now hugely enlarged 
Compared with { TAIL ~ a flow } without { HEAD ~ a radius } , the backflow bubble 50 is now hugely enlarged
OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH