J-20... The New Generation Fighter II

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siegecrossbow

siegecrossbow

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J-10 took a very long time to develop because of the engine issues. However I think there is no reason why the initial batch of J-20s couldn't use Russian engines. An AL-31 variant with thrust vectoring capabilities was displayed at Zhuhai last year.
 
siegecrossbow

siegecrossbow

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A link to Feiyang which demonstrates, via diagrams, how the adjustable DSI inlet could work.

Please, Log in or Register to view URLs content!


remove the space between fy and js if you want to go to the site.
 
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latenlazy

Brigadier
Centrist said:
Can someone explain this?
Click to expand...

The link? Or the mechanics?
The link was broken up by a space because **** is autodetected as malware on this message board.

The link itself indicates that the lip of the inlet can slide. Don't ask me how that makes the DSI adjustable, though, the labels only talked about the mechanics of a sliding inlet lip.
 
C

Centrist

Junior Member
latenlazy said:
The link? Or the mechanics?
The link was broken up by a space because **** is autodetected as malware on this message board.

The link itself indicates that the lip of the inlet can slide. Don't ask me how that makes the DSI adjustable, though, the labels only talked about the mechanics of a sliding inlet lip.
Click to expand...

I meant how that makes it adjustable.
 
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latenlazy

Brigadier
Centrist said:
I meant how that makes it adjustable.
Click to expand...
When the lip moves it lets more air in and changes the obliqueness of the shock wave entering. He didn't get into specifics about how that changes the airflow, but my guess is that when you reach higher speed the shockwave entering the inlet gets more oblique, and retracting the lip prevents the incoming shockwave from generating turbulence when it runs into it.

Giving it some more thought, a simplified explanation could be that retracting the inlet lip changes the angle of the shock wave ramp relative to the DSI bump. That would make sense since the cowl (the lip) is an important part of blocking the boundary layer of turbulent air, but I have no clue how making that retractable helps slow the air for the engine at supersonic speeds.

Someone with more knowledge of aerodynamics will have to fill us in.
 
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Deino

Deino

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Can anyone confirm that the J-20 flew twice today ??

Reportedly the third flight was from 3:30 to 4:24 PM for 55 minutes (with wheels retracted at 3:37) and the fourth flight from 5:50 to 6:47 PM for 57 minutes.
 
C

Centrist

Junior Member
latenlazy said:
When the lip moves it lets more air in and changes the obliqueness of the shock wave entering. He didn't get into specifics about how that changes the airflow, but my guess is that when you reach higher speed the shockwave entering the inlet gets more oblique, and retracting the lip prevents the incoming shockwave from generating turbulence when it runs into it.

Giving it some more thought, a simplified explanation could be that retracting the inlet lip changes the angle of the shock wave ramp relative to the DSI bump. That would make sense since the cowl (the lip) is an important part of blocking the boundary layer of turbulent air, but I have no clue how making that retractable helps slow the air for the engine at supersonic speeds.

Someone with more knowledge of aerodynamics will have to fill us in.
Click to expand...

Is this system the first of its kind?
 
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