Accordingly, {HEAD ~ the outer passage} 11 has an annular cross section, whereas {TAIL ~ the inner passage} 10 has a full cross section 
Accordingly , { HEAD ~ the outer passage } 11 has an annular cross section , whereas { TAIL ~ the inner passage } 10 has a full cross section
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH