The spiral flow increases the rate of convection and thus increases {HEAD ~ the cooling capacity} of {TAIL ~ the cooling system} 
of
The spiral flow increases the rate of convection and thus increases { HEAD ~ the cooling capacity } of { TAIL ~ the cooling system }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL