What is this in the SGT5-4000F picture? 1

[aafuni]

Siemens has this picture of the SGT5-4000F turbine on their website:

http://www.siemens.com/press/pool/d...file_sopg200603_01_300dpi_1387041_1454206.jpg

What is the silvery squiggle attached to the row 4 blades? It looks a bit like a thermocouple, but you wouldn't put those on every blade and you wouldn't have the line run squiggly back and forth like that.

Let me know if anyone knows anything about this.
Thanks
-AAFuni

 

[ScottyUK]

I wonder if it really is a t/c and if this is a development engine? There are number of other cables - thermocouples? - on the outer casing near row one which I don't think are standard fitment either. The engine has clearly been fired but the blading looks newly fitted.


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If we learn from our mistakes I'm getting a great education!

 

[aafuni]

Yeah, I am guessing it is a development engine. If it is, another possibility would be that it is a strain gage. They say that they run harmonics and vibration testing on the entirety of row 4 using strain gages (BSSM). Once again I don't think stain gages would be configured in such a manner, with all the squiggles in the line.

 

[rmw]

If I had seen it without your asking, I would have taken it for a strain gage. The routing of the wiring may be to make sure that blade flexure or torsion doesn't break the epoxy bond that holds the leads in place. Temperature could be take by a probe right in front of the blade row via conventional means.


rmw

 

[rotorblade]

I agree with rmw.

It is common practice to avoid straight lines in the instrumentation routing to account for deformations, thermal expansion & contraction, etc.

Regards,

rotorblade

 

[aafuni]

Thanks guys. I am pretty sure you must be right about it being a strain gauge it looks like something of that nature.

 

[rotorblade]

I have to add that this looks very similar to a high temperature strain gauge that we had applied on a non-rotating aero engine component.