Such a process is distinguished in that the surface experiencing the air pressure is convex and {HEAD ~ the normals} to {TAIL ~ the surface} converge on the rounded shaping vertex of the shaper 
to
Such a process is distinguished in that the surface experiencing the air pressure is convex and { HEAD ~ the normals } to { TAIL ~ the surface } converge on the rounded shaping vertex of the shaper
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 OTH OTH OTH OTH OTH OTH OTH OTH