Page 194 - The Jet Engine

Water injection

Fig. 17-4 A typical combustion chamber injection system.

supply of oil. The degree of servo valve opening is inlet Movement of the throttle control to the take-off
set by a control system that is sensitive to propeller position opens the oil cock, and the oil pressure
shaft torque oil pressure and to atmospheric air passes through the servo valve to open the metering
pressure acting on a capsule assembly. valve by means of the servo piston.
6. The control unit high pressure oil cock control COMBUSTION CHAMBER INJECTION
lever is interconnected to the throttle control system 7. The combustion chamber injection system
in such a manner that, until the throttle is moved shown in fig. 17-4 is a typical system for a turbo-jet
towards the take-off position, the oil cock remains engine. The coolant flows from an aircraft-mounted
closed, and thus the metering valve remains closed, tank to an air-driven turbine pump that delivers it to a
preventing any mixture flowing to the compressor water flow sensing unit. The water passes from the

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