Furthermore, the larger, and volume configurable duct volume behind the fan represents a volume into which the fixed intake aperture air volume is fed, thus representing a diffusion of the intake air mass, and a consequent pressure drop in {TAIL ~ the duct} behind {HEAD ~ the turbine type fan} 
Furthermore , the larger , and volume configurable duct volume behind the fan represents a volume into which the fixed intake aperture air volume is fed , thus representing a diffusion of the intake air mass , and a consequent pressure drop in { TAIL ~ the duct } behind { HEAD ~ the turbine type fan }
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 OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD