Jawed
Topic Author
Posts: 312
Joined: Mon Sep 18, 2006 10:47 am

Little Stick (or Probe?) In Engine Intake?

Thu Nov 29, 2007 11:39 pm

What is this component that sticks into the engine intake? It looks like something that may measure pressure in front of the engine blades. Is that what it is?

It's clearly visible on the inside wall of the engine here:

http://www.airliners.net/open.file/1065799/L/
http://www.airliners.net/open.file/1280417/L/

Do other engines, like the GE90 also have this?

[Edited 2007-11-29 15:39:55]
 
EMBQA
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RE: Little Stick (or Probe?) In Engine Intake?

Thu Nov 29, 2007 11:44 pm

Quoting Jawed (Thread starter):
Do other engines, like the GE90 also have this?

Most all engines have that. It's the ITT probe. It measures the air temp at the inlet

GE90
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[Edited 2007-11-29 15:56:00]
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avt007
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RE: Little Stick (or Probe?) In Engine Intake?

Fri Nov 30, 2007 2:21 am

EMBQA is very close, but since this is Anet, I'll nitpick. It is a temperature probe, known as T2 on some GEs. It does indeed measure inlet temp.
ITT stands for interturbine temperature, referring to the temperature between the high pressure and low pressure turbines.

[Edited 2007-11-29 18:32:34]
 
Fly2HMO
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RE: Little Stick (or Probe?) In Engine Intake?

Fri Nov 30, 2007 2:43 am



Quoting Avt007 (Reply 2):
ITT stands for interturbine temperature.

Probes which AFAIK, are not visible from the exterior, at least not with the cowls closed.

Quoting Avt007 (Reply 2):
It is a temperature probe, known as T2 on some GEs. It does indeed measure inlet temp.

IIRC in most engines they sense pressure too, which is then used for to calculate EPR (Engine Pressure Ratio) by comparing pressures with a sensor in the exhaust side of the engine.

Been a while since my turbines class so someone correct me if I'm wrong.
 
avt007
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RE: Little Stick (or Probe?) In Engine Intake?

Fri Nov 30, 2007 2:54 am

ITT probes are buried in the engine, directly in the hot gas path. You can see the harnesses from outside if the cowls are removed. On the CF34, the T2 probe is only for temperature, it uses a pressure sensor on the FADEC module for pressure. Or alternately, some aircraft may use air data computer static pressure values. I wouldn't be surprised if you're right, and some manufacturers use dual temp/pressure probes.
 
ex52tech
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RE: Little Stick (or Probe?) In Engine Intake?

Sun Dec 02, 2007 8:39 pm



Quoting FLY2HMO (Reply 3):
IIRC in most engines they sense pressure too, which is then used for to calculate EPR (Engine Pressure Ratio) by comparing pressures with a sensor in the exhaust side of the engine.


Many of the newer aircraft take the Pt2 reading off the nose of the aircraft, or some location other than the inlet of the engine. Less plumbing in the nose cowl, and less plumbing in the pylons. The EPR transducer can be located someplace other than the pylon also.
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G4Doc2004
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RE: Little Stick (or Probe?) In Engine Intake?

Mon Dec 03, 2007 5:18 pm

Some engines also use a TGT probe, such as the older CJ610 engine, as well as APU's. This probe is visible if you look up the tailpipe, as it is aft of the last stage turbine wheel.
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