{TAIL ~ The intake opening}, {HEAD ~ the propulsion device}, and the conduit define a flow path for the flow of air and particulates and in one embodiment, the flow path has an approximately constant flow area from the intake opening to the propulsion device 
{ TAIL ~ The intake opening } , { HEAD ~ the propulsion device } , and the conduit define a flow path for the flow of air and particulates and in one embodiment , the flow path has an approximately constant flow area from the intake opening to the propulsion device
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH