FM 1-506 Fundamentals of Aircraft Power Plants ... - Survival Books

WWW.SURVIVALEBOOKS.COMFM 1-506RPM and airflow, a narrow pattern is required to keepthe flame of combustion away from the walls of thecombustion chamber (Figure 4-6{B]). The small fuelflow used in idling is broken up into a fine spray after beingforced through a small outlet formed by the primaryholes. The secondary holes are larger but still provide afine spray at higher RPM because of the higher fuelpressure.For the duplex nozzle to function, there must be adevice to separate the fuel into low- (primary) and high­(secondary) pressure supplies. This flow divider maybeincorporated in each nozzle, as with the single-entryduplex type (Figure 4-6[C]), or a single-flow divider maybe used with the entire system (Figure 4-6[D]).Single-entry duplex nozzles incorporating an internalflow divider require only a single fuel manifold4-7