Moving the vent location to {HEAD ~ either side} of the vent follower causes fluid or gas to escape from one or {TAIL ~ the other cell} 
Moving the vent location to { HEAD ~ either side } of the vent follower causes fluid or gas to escape from one or { TAIL ~ the other cell }
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL