{HEAD ~ Water} flowing through {TAIL ~ the intake grate} flows through the concavity in a laminar flow and encounters no obstacles other than the elongate drive shaft before encountering the impeller 
flowing through
{ HEAD ~ Water } flowing through { TAIL ~ the intake grate } flows through the concavity in a laminar flow and encounters no obstacles other than the elongate drive shaft before encountering the impeller
HEAD HEAD HEAD HEAD HEAD 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 OTH OTH OTH OTH