Just playing it safe. I'm not that well-versed in engines.
PRC VCE and low bypass engines (fighters, tactical jets, UAVs, others)
- Thread starter 00CuriousObserver
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Just playing it safe. I'm not that well-versed in engines.
The 2 stage LPT is bizarre though. I'd expect the WS-21 to be a 3-7-1-1. In fact even the RD-33 family it's related to never had a 2 stage LPT configuration.
I think it’s 3 stage LPT. The fan is shrouded.
Turbine, not compressor. There are 3 low pressure compressors and 2 low pressure turbines.
Oh oops.
How so? In many (such as F-404) low bypass turbofan, the bypass happens (air flow split) between LPC and HPC. This makes the LPC nearly equal to Fan. In F-404 there are 3 stages of Fan/LPC, in other words 1 Fan stage + 2 LPC stages. WS-21 has the same configuration of F-404 family. RD-33 is different, it does have 1 Fan + 3 LPC or 4 fan/LPC stages. The confusion of counting stages is caused by whether fan and LPC are counted separately or combined.
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Bro is talking about how the engine has three turbine stages. A high pressure one and 2 low pressure ones. Which is odd, because both WS-13 and RD-33 only have two turbine stages, 1 high and 1 low.. HPT drives the HPC, LPT drives both the fan and the LPC. The WS-21 seems to have chosen the path to draw more energy out of the core stream to power the Fan and LPC's.
Both the WS-13/RD-33 have 4 LPC stages while the WS-21 only has 3. What could be the thought process and benefits of adding the second LPT stage?
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oops. My mistake looking at LPT but thinking of LPC.
But 2 low pressure turbine isn't unusual. And why should WS-21 be considred to be related to RD-33? P.S. I don't buy the rumor that WS-21 is somehow improved version of RD-33 derivatives.
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Thank you. Confused how this mistake was made not once, but twice...
Tbh, there's a non-zero chance this is just a non-descript model of no significance and just a placeholder. A 3-7-1-2 configuration genuinely makes no sense for a F414-class engine, considering how this engine supposedly is derived from both the RD-33 and F404, both of which only has one LPT stage. As @Nx4eu said, an addition of an LPT stage while going from a 4 to 3 stage LPC is very odd, again, considering the size.
It’s probably related to bypass ratio. Larger fan. F110 and F135 both have to 2 LPT. F119, EJ200 and F414 all have 1 LPT.