Date: 16 Jun 97 21:35:39 From: Iain Stuart <firstname.lastname@example.org> Organization: What References: 1
View raw article or MIME structure
In article <airliners.1997.1226@ohare.Chicago.COM>, Rich Nute <email@example.com> writes >A jet engine is started by: > >1. Spin the turbine up to some rpm. > > How many rpm? On RB211's about 25% of max HP speed - About 3,000 rpm The other shafts of a multi-shaft engine are obviously slower. > > How is the spin air injected into the engine? There's an external gearbox fitted with a air starter motor, and generators and pumps. Pressurised air is fed in (from other APU, engines or ground carts) driving the starter, driving the gearbox, a shaft into the core of the engine, and driving the HP system. During the start, the starter disengages once the ngine is self-sustaining. Once running above idle, the HP system drives the gearbox, providing electrical and hydraulic power to the aircraft. >2. Inject fuel. > How is this done? Thru' fuel injectors feeding fuel directly into the combustion chamber. >3. Ignite fuel. > How is this done? Ignitor plugs ( big spark plugs ) but once started, they're not required and the combustor is self sustaining. (You can switch on continuous ignition if you have a nervous pilot. ;-) ) >In the cockpit, what are the engine start controls, >and what are the pilots' jobs during engine start? With modern aircraft systems, press the autostart button, and wander off for a few mins while the electronics take care of everything. >Doesn't one pilot keep a hand on the engine fire extinguisher? Only if he's a nervous wuss ;-) >Thanks, >Richard Nute Welcome ! Big-Iain ps. Rolls-Royce's UK Homepage has a "How A Jet Engine Works" section. -- Iain Stuart Anybody know how to stop pandas breeding ? Got a pair as a Christmas present last year, and all they do is breed and eat. "At it" like rabbits they are, horny little buggers. The police are getting suspicious about my sales of stuffed pandas, and the market for live pandas is almost saturated !