{HEAD ~ This radius R} is selected in {TAIL ~ such a way} that the flow comes into contact with the wall and thus causes the swirl coefficient to increase considerably 
is selected in
{ HEAD ~ This radius R } is selected in { TAIL ~ such a way } that the flow comes into contact with the wall and thus causes the swirl coefficient to increase considerably
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH