The cross section of flow of the tube 20 in this region is given a transition radius R, the size of which in principle depends on {HEAD ~ the flow} inside {TAIL ~ the tube} 20 
inside
The cross section of flow of the tube 20 in this region is given a transition radius R , the size of which in principle depends on { HEAD ~ the flow } inside { TAIL ~ the tube } 20
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 HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH