Kcle From United States of America, joined Feb 2001, 686 posts, RR: 0 Posted (11 years 12 months 21 hours ago) and read 1356 times:
While spotting at CLE, a person will see many MD-80s in a short amount of time, so, there are a lot of JT8D turbofans here. While taxiing, i noticed the engines' main intake turbines weren't moving. Why is this, and do these main intake turbines ever turn?
Wilcharl From United States of America, joined Jun 2000, 1158 posts, RR: 3 Reply 1, posted (11 years 12 months 19 hours ago) and read 1304 times:
Those "turbines" are the inlet guide vanes. The turbine section is located aft of the combusters. There was talk of this earlier. If you ever want to freak out a pax on a DC-9 tell them the airline has decided to institute fuel saving measures by shuting the engines off during the decent and gliding in, if he doesnt believe you tell him to look @ the engine, they will look out the window and see the IGV's and freak out.
Wilcharl From United States of America, joined Jun 2000, 1158 posts, RR: 3 Reply 3, posted (11 years 12 months 18 hours ago) and read 1281 times:
yeah the last row of a DC-9 you get a view of nothing, just forward of that you get a ncie view of the cowling, if you sit in row about 25(on an FL DC-9) you can get a nice view of the engine. whats great is a night flight on a 717 when the strobes fire you can look back and see the live fan of the BR-715
Airplay From , joined Dec 1969, posts, RR: Reply 4, posted (11 years 12 months 7 hours ago) and read 1257 times:
Just a clarification.
In simplistic terms, the "turbines" are downstream of the combustion chamber of the engine. They extract power to run the compressor and/or propeller or fan (if applicable) at the other end of the engine. In jet engines the turbines are at the rear and the compressor is at the front. Not always the case with turboprop engines like the PT-6 where the air flow starts at the rear of the engines and ends at the exhaust stacks at the front of the engine.
Guide vanes are usually incorporated thoughout the engine to optimize the direction of the air to allow the proper angle over the compressor and turbine blades which are really small airfoils. The engine is optimized usually at one critical power setting.
Many modern jet engines utilize variable guide vanes to allow optimization at several power settings.