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Old 28th Nov 2020, 19:10
  #74 (permalink)  
kontrolor
 
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Originally Posted by iranu
Just to add to DaveReidUK's comment. The pictures posted of the disc segment with blade roots and 2 damaged blades still attached is a fan disc (LPC) not a turbine disc.

I can't post links, but there are engine schematics for the D-18T online. It's a 3 spool engine with a single stage LPC/Fan. The IPC and HPC use dovetail blade roots, whilst the 3 turbine sections use fir-tree roots. I originally thought the disc segment was the HPT due to those fir-tree roots, but on seeing the remainder of the engine on the wing and a wider shot of the disc segment I concluded that it's part of the LPC/Fan disc. If you look at the 2 damaged blades you can see that the blades lack air cooling (HPT and IPT are cooled on this engine), whilst the blade length and chord are too large to be turbine blades. If you look at the blade nearest the camera you can see that it's fractured along the line of the snubber, again indicating this is part of the fan disc.

We won't know what caused the failure until a full metallurgical analysis is performed, which may be dependent on the missing disc fragment(s) being found.

Turbine disc failure modes are for another topic.



1-Cone leading edge section; 2-Fan wheel; 3-Fan shaft with bearing support; 4-Fan casing; 5-Fan straightener vane; 6-Intermediate pressure compressor; 7-Jet nozzle; 8-Exhaust cone; 9-Rear mount; 10-Rear bearing; 11-Fan turbine; 12-Intermediate pressure turbine rotor; 13-Turbine bearings casing; 14-High pressure turbine rotor; 15-Combustion chamber with hight pressure turbine; 15.1-High pressure turbine nozzle guide vanes; 15.2-Combustion chamber; 16-Thrust reverser; 17-Engine master module; 17.1-Accessory drive gear box; 17.2-Intermediate drive.


source: http://www.buran-energia.com/mriya-a...ine-consti.php

http://www.buran-energia.com/mriya-a...ngine-desc.php

Last edited by kontrolor; 28th Nov 2020 at 19:12. Reason: added caption
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