The J-20-engine discussion is over and other speculative topics ... to separate from the J-20-news !

[Armchair]

Anybody has any info on whether the canards of the j-20 harm its RCS in a way that the canard delta design is less stealthy than a conventional layout? Are there any RCS studies that proves this point?

 

[ozranger]

Anybody has any info on whether the canards of the j-20 harm its RCS in a way that the canard delta design is less stealthy than a conventional layout? Are there any RCS studies that proves this point?

There are a couple of academic papers in Chinese iterate through several defection angles with corresponding RCS test results and propose solutions for technical improvement. The conclusion is RCS has no significant increase on small angles, say <10 degree.

Remember big canard deflection is only being used for take-off and pitch down control at high angle of attack. In latter situation the aircraft already enters dog fight so big deflection angles will not be a problem as both sides can already see each other visually.

During flight time canards mostly remain stationary. Ailavators are being used for ascending and descending. During supersonic cruise or supersonic maneuver the canards will deflect slightly to provide the nose additional lift. But the angle is much smaller than that created by elevators on a tail aft aircraft's horizontal stabilizers.

 

[serenity]

Easy. Think about why some European and Swedish independent 5th generation concepts also use canards. Also American concepts for 5th gen from Boeing used canards. Same with 5.5 gen concept drawings. If we are not experts in this field, then it is impossible to say but remember the facts many 5th gen and 5.5 gen considered using canards.

 

[laser911]

Anybody has any info on whether the canards of the j-20 harm its RCS in a way that the canard delta design is less stealthy than a conventional layout? Are there any RCS studies that proves this point?

If you think about how the radar work, you will have a better idea about this RCS problem. The radar requires a certain accumulation of signal (in terms of strength or time) to recognise something as a target. The idea of stealth is reducing the RCS to noise level so that the radar will ignore it. During level flying, the control surface only move slightly for a very short time (less than 1 second) to adjust the aircraft, therefore the signal wont be significant and will only last a very short time. Hence it is difficult to pick up by radar.

 

[vi-va]

Anybody has any info on whether the canards of the j-20 harm its RCS in a way that the canard delta design is less stealthy than a conventional layout? Are there any RCS studies that proves this point?

better RCS on 90 degree. cannard itself do NOT affect RCS.

Many academic papers, you can search around.

 

[dbc]

better RCS on 90 degree. cannard itself do NOT affect RCS.

Many academic papers, you can search around.

Sure those 'papers' will be very useful once you reveal the materials used to make the J-20 canard.
Do you know?

 

[PeacefulWar]

Sure those 'papers' will be very useful once you reveal the materials used to make the J-20 canard.
Do you know?

Your arguments really don't make sense.
The debate is about whether the canards(the design the geometry itself) will affect RCS.
Why suddenly bring material in? Stealth materials used in main wings can't be used on canards?
Logic please.

 

[dbc]

Your arguments really don't make sense.
The debate is about whether the canards(the design the geometry itself) will affect RCS.
Why suddenly bring material in? Stealth materials used in main wings can't be used on canards?
Logic please.

Really? Logic? No, because carbon composites cannot withstand torsional loading experienced by the canard of a highly maneuverable Mach capable fighter jet. It is possible the but unlikely the Chinese came up with a RAS composite that can withstand the load - I have never heard of any such an application across the aerospace industry.Hence my question about the materials of J-20 canard. Do you know what it is made from? If so, please enlighten us.

 

[vi-va]

Really? Logic? No, because carbon composites cannot withstand torsional loading experienced by the canard of a highly maneuverable Mach capable fighter jet. It is possible the but unlikely the Chinese came up with a RAS composite that can withstand the load - I have never heard of any such an application across the aerospace industry.Hence my question about the materials of J-20 canard. Do you know what it is made from? If so, please enlighten us.

1. I and many others bet on academic papers instead of yours. This is logical.
2. If J-20 sucks, good luck to America. They should NOT be panic as we see today.
3. Please stop nonsense, it's endless and meaningless. Argument is valid when you bring value to others. I don't see it.

 

[dbc]

1. I and many others bet on academic papers instead of yours. This is logical.
2. If J-20 sucks, good luck to America. They should NOT be panic as we see today.
3. Please stop nonsense, it's endless and meaningless. Argument is valid when you bring value to others. I don't see it.

blah blah! pointless rambling attempt at deflection. Can you tell us the material composition of the J20 canard?

 

[PeacefulWar]

Really? Logic? No, because carbon composites cannot withstand torsional loading experienced by the canard of a highly maneuverable Mach capable fighter jet. It is possible the but unlikely the Chinese came up with a RAS composite that can withstand the load - I have never heard of any such an application across the aerospace industry.Hence my question about the materials of J-20 canard. Do you know what it is made from? If so, please enlighten us.

Thanks for at least explaining your point.
Nope, I have no idea what material J-20 used for canards.
Since you bring this topic. Please share your sources that proves your point?

blah blah! pointless rambling attempt at deflection. Can you tell us the material composition of the J20 canard?

Feel free to make a point with sources or reasoning instead of one line "pointless rambling attempt at deflection".
I'm happy to learn from different point of views.
But one line trolling? Thanks, But no thanks.

 

[Ultima Thule]

blah blah! pointless rambling attempt at deflection. Can you tell us the material composition of the J20 canard?

Why do assume that they build of conventional materials its classified
And do you know what materials are being used in f-22 and F35????

 

[samsara]

blah blah! pointless rambling attempt at deflection. Can you tell us the material composition of the J20 canard?

Stop asking thing that is not publicized! Don't flash this thread time and again with questions that you know no one knows the answer for its data is just classified! Visit SDF if you love such thing!

 

[dbc]

Thanks for at least explaining your point.
Nope, I have no idea what material J-20 used for canards.
Since you bring this topic. Please share your sources that proves you

I don’t know and that is the point isn’t it. On the Typhoon and Rafale, the canard is made with diffusion bonded titanium- this information is provided by Airbus and Dassault respectively. But not so in the case of the J-20, it isn’t known and yet many here assume it (the canard) is made from Radar Absorbing composites.

So on all three 4.5 gen delta canard European fighter the canard is made from Titanium. It is possible the Chinese invented a material that is radar absorbing and also provides the same strength and resilience to dynamic loading forces as titanium. If such a material has been engineered by anyone it will be huge news not a state secret.

 

[samsara]

I don’t know and that is the point isn’t it. On the Typhoon and Rafale, the canard is made with diffusion bonded titanium- this information is provided by Airbus and Dassault respectively. But not so in the case of the J-20, it isn’t known and yet many here assume it (the canard) is made from Radar Absorbing composites.

So on all three 4.5 gen delta canard European fighter the canard is made from Titanium. It is possible the Chinese invented a material that is radar absorbing and also provides the same strength and resilience to dynamic loading forces as titanium. If such a material has been engineered by anyone it will be huge news not a state secret.

Unlike the European makers, China does not export J-20 thus it needs not to publicize the J-20 data! I hope this simple fact makes it pretty clear to you. China has no need to divulge such data!