GE MS9001 mystery hole

[aafuni]

I am wondering what this hole is for on the inner side wall of MS9001 parts. The hole is into the trailing edge section of the core cavity. Some suppliers have been adding it during machining so it is not casting related. I have seen parts with this hole, and several without it. I know the main hole gets plugged down the line, but what about this one?

 

[aafuni]

Here is an image of a part without the hole.

 

[abeltio]

The two parts are significantly different, the part with the hole does not have the faired cooling holes that the part without the cooling holes has.

This seems like a 1st stage nozzle partition, because of the size and the partition wall cooling holes.

That hole could very well be a relief hole to allow venting of gases during the casting cooldown (and avoid cracking)

Being so small and just one of it, it will not affect the performance, life or wear of the part.


saludos.
a.

 

[aafuni]

abeltio,
Sorry that one picture was taken before the faired cooling holes were added. You are right that it is a first stage.

So to the best of your knowledge this hole has nothing to do with cooling during operation? I am running some analysis on the cooling flow and want to know if this hole would be covered in operation, as the main core end is, or if it is free to flow through this hole.

Thanks

 

[abeltio]

Now i don't understand your question.

In any case: to analyze cooling flows you need to know a lot of details that GE will not provide: flow of air for combustion vs. flow of air for cooling. length and diameter of internal passages (to know the cooling air pressure when entering the nozzle), pressures and temperatures outside the nozzle. metal temperatures (including tbc effect), etc.

cheers

saludos.
a.

 

[aafuni]

abeltio,
As I said, the question is simply what are those holes. I have everything else figured out. I am just curious as to why some of the frame 9e first stage nozzles I am seeing have that hole, while others do not.

 

[Romefu12]

aafuni
To specifically answer your question it might help to post a part number and casting number as GE has many iterations of nozzle segements for all frame sizes / firing temperatures etc

Kind Regards
Romefu12