Chengdu J-20 5th Generation Aircraft News & Discussions

[gambit]

Sir does the ellipsoid like the j-20's actuators apply to the 10-lambda rule?

Any time you have a physical path where a portion of the wave can POTENTIALLY return or wrap around to the point of impact, the 10-lambda rule is in play. It does not mean there will be such a wrap around travel, it just mean that there is a physical path where this potentiality exist.

 

[antonius123]

Right here...


A 'bigger RCS' is possible only if those moving parts are exposed to radar bombardment.

Here is the F-111 that have a quarter cone, called a 'spike', that not only translate fore/aft but also expand or 'blossom' to become larger...

F-111 Inlets

I was on the F-111 for 5 yrs. Never have I seen any exposed moving parts on the spikes. So if we can do it for the F-111's intake system, we can do the same for the conical intake.

So show us a source that have a jet engine aircraft with a conical intake that have exposed moving parts.

Sorry not to reply you soon as I am traveling for 2 weeks now.

Why do you think the traveling wave could reach the moving parts?
And why do you think the cone itself will not contribute to RCS?

What else does it use?

Radar - Wikipedia, the free encyclopedia

There is no such thing as radar specific type of EM wave. Believe it or not, technically speaking, radar is a method of communication and it uses radio type waves.

Then explain how this way of work will absorb the "traveling wave" ?

 

[antonius123]

@ Gambit,

Its funny and hilarious to see your fanboyism claim in Thread: China's Blitzkrieg on U.S. Carrier that China will have the same fate as Serbia

You are simply equating China's military power with Serbia is again demonstrating your idiocy and fanboy mentality of old guy.

Serbia have no ability to blow down US' Satellites, nor can not screw US military information infrastructure.

Do you think the tomahawk could hit the target without the help of Satelite?
Do you think B-2 and F-22 could easily reach china coast unnoticed and will freely enter China's air without facing china air defense system (J-10, J-11B, J-20, anti stealth radar, HQ9, HQ-15, etc), and freely drop the bomb there?

Shame on you

 

[gambit]

Why do you think the traveling wave could reach the moving parts?

Do not try to evade.

Here is YOUR post...

Do you understand that Cone will be heavier, and the moving parts contributes bigger RCS?

The only way the mechanisms that translate the cone's position could increase RCS is to be exposed. So according to YOUR post, such exposure does exist. So show us a source that have a jet engine-ed fighter with a conical intake with exposed cone translating mechanisms.

And why do you think the cone itself will not contribute to RCS?

Did I say it does not?

Then explain how this way of work will absorb the "traveling wave" ?

You are stupid if you have to ask.

One more chance...

Q: In designing a variable sweep wing system, like that on the F-111, what role does the wing's pivot point have on its aerodynamics?

 

[antonius123]

Do not try to evade.

Here is YOUR post...

The only way the mechanisms that translate the cone's position could increase RCS is to be exposed. So according to YOUR post, such exposure does exist. So show us a source that have a jet engine-ed fighter with a conical intake with exposed cone translating mechanisms.

I did not evade

My questions is very much related to your question; if you dont catch/understand where I am asking about it means you dont know what you are talking about.

Let me make my question a bit clearer : Why do you think the traveling wave could not reach the moving parts (of the Mig-21's cone)?

You are stupid if you have to ask.

One more chance...

Q: In designing a variable sweep wing system, like that on the F-111, what role does the wing's pivot point have on its aerodynamics?

This is what should be called : "trying to evade" of yours

Dont start to play diverting.

Again I am asking you: "explain how this way of work will absorb the traveling wave ?"

If you cannot answer, it means you dont know what you are trying to explain regarding the picture you drag.

 

[gambit]

I did not evade

My questions is very much related to your question; if you dont catch/understand where I am asking about it means you dont know what you are talking about.

Let me make my question a bit clearer : Why do you think the traveling wave could not reach the moving parts (of the Mig-21's cone)?

Yes, you did evade.

Let us examine your post...

Do you understand that Cone will be heavier, and the moving parts contributes bigger RCS?

You said 'and' because you believe that the translation mechanism are EXPOSED in some ways where radar signals could make impact and make those mechanisms contributors to the final RCS.

So here is the MIG-21's nosecone...

SqC: MiG-21 PFM Nosecone | Flickr - Photo Sharing!

I see no EXPOSED moving parts there.

Now it is your turn to show us how smart and knowledgeable you are about aviation by showing us a jet engine-ed fighter with a conical intake that have EXPOSED moving parts.

This is what should be called : "trying to evade" of yours

Dont start to play diverting.

Again I am asking you: "explain how this way of work will absorb the traveling wave ?"

If you cannot answer, it means you dont know what you are trying to explain regarding the picture you drag.

Indeed I can answer. But so far we have yet to see you make any TECHNICAL contribution in this forum.

Here is an example of what I contributed...

http://www.defence.pk/forums/chinese-defence/187501-clearest-j-20-pictures-6.html#post3068542

Keep in mind that you claimed to have aviation 'background' and 'study' and tried to use that to shut down the Indians. Now why not show us how knowledgeable you are by explaining how a radar absorber material (RAM) work. Never mind what I may know or does not know. A PhD or a high school student can pose the same question and both can expect an answer. So it does not matter if I know anything or not. You tried to shut down the Indians, now here is your chance to show them why they should listen to you and not to me.

Finally...

Q: In designing a variable sweep wing system, like that on the F-111, what role does the wing's pivot point have on its aerodynamics?
A: Affects the wing's center of pressure (CP).

Center of Pressure

Swing Wings | Flight Today | Air & Space Magazine

The flow needed to move the wings aft was about double that, and was accomplished with a variable displacement pump. The reason for the mismatch was that the positioning of the wing pivot in relation to the wing's center of pressure made it easier to unsweep than to sweep.

On the F-111, the pivot locations were relatively inboard, resulting in excessive trim drag at transonic and supersonic conditions. Tomcat designers were not going to repeat that mistake.

"In those days, [the Navy] wanted high-altitude maneuverability," says Tom Lawrence, a NAVAIR aerodynamics expert who evaluated this capability for the Tomcat. "If you had the wing pivots closer to the fuselage, you get a very large shift in the center of pressure" when the wing changes its angle of sweep. That could lead to the kind of instability that killed Raymond Popson in the X-5.

You did not know this.

Considering you claimed to have aviation 'background' and 'study' and tried to use that to shut down the Indians, this make a dozen basic aerodynamics and six flight controls engineering questions you do not know.

Next...

Q: What does asymmetrical thrust and yawing moment affects?

We still have these areas to go through: Instrumentation, Navigation, Communication, Radar, Fuel, Propulsion and Sheetmetal.

 

[Esc8781]

You guys should take a chill pill. Just ignore and there you go problem solved

 

[antonius123]

Yes, you did evade.

Let us examine your post...


You said 'and' because you believe that the translation mechanism are EXPOSED in some ways where radar signals could make impact and make those mechanisms contributors to the final RCS.

So here is the MIG-21's nosecone...

SqC: MiG-21 PFM Nosecone | Flickr - Photo Sharing!

I see no EXPOSED moving parts there.

Now it is your turn to show us how smart and knowledgeable you are about aviation by showing us a jet engine-ed fighter with a conical intake that have EXPOSED moving parts.

When did I said the moving parts of the Cone is exposed??

You like to twist people argument just like your like of lying and faking

Indeed I can answer. But so far we have yet to see you make any TECHNICAL contribution in this forum.

Nooo you are obviously trying to evade

Here is an example of what I contributed...

http://www.defence.pk/forums/chinese-defence/187501-clearest-j-20-pictures-6.html#post3068542

Keep in mind that you claimed to have aviation 'background' and 'study' and tried to use that to shut down the Indians. Now why not show us how knowledgeable you are by explaining how a radar absorber material (RAM) work. Never mind what I may know or does not know. A PhD or a high school student can pose the same question and both can expect an answer. So it does not matter if I know anything or not. You tried to shut down the Indians, now here is your chance to show them why they should listen to you and not to me.

Finally...

Q: In designing a variable sweep wing system, like that on the F-111, what role does the wing's pivot point have on its aerodynamics?
A: Affects the wing's center of pressure (CP).

Center of Pressure

Swing Wings | Flight Today | Air & Space Magazine

You did not know this.

Considering you claimed to have aviation 'background' and 'study' and tried to use that to shut down the Indians, this make a dozen basic aerodynamics and six flight controls engineering questions you do not know.

Next...

Q: What does asymmetrical thrust and yawing moment affects?

We still have these areas to go through: Instrumentation, Navigation, Communication, Radar, Fuel, Propulsion and Sheetmetal.

What kind of contribution if you can only do copy paste and drag article from the internet, but has no adequate understanding?

Remember you have drag a lot of article with missunderstanding? one of example is the article that you claim as explaining 120 degree corner reflector.

Your understanding is the important thing here, not the article that you drag

 

[gambit]

When did I said the moving parts of the Cone is exposed??

Right here...

Do you understand that Cone will be heavier, and the moving parts contributes bigger RCS?

Cannot evade. Even if you were to go back and edit it out to cover up your stupidity, it is too late. Too many knows.

You like to twist people argument just like your like of lying and faking

People can see who is really twisting here -- YOU.

Nooo you are obviously trying to evade

What kind of contribution if you can only do copy paste and drag article from the internet, but has no adequate understanding?

Then show us what you do know. Remember, YOU claimed to have an aviation 'background' and 'study' and tried to use that to shut down the Indians. So show us what you do know.

One more time...

Q: What does asymmetrical thrust and yawing moment affects?

It does not look good for you, buddy.

You guys should take a chill pill. Just ignore and there you go problem solved

And lose the fun? No problem here. Actually, the ones with the real problem are the Chinese crowd. This Indonesian suck-up is doing a terrible job at defending the J-20.

 

[antonius123]

Right here...


Cannot evade. Even if you were to go back and edit it out to cover up your stupidity, it is too late. Too many knows.


People can see who is really twisting here -- YOU.

Ow really??

Then show me and the readers where the word "exposed" in that sentence of mine!

I bet you will again caught twisting and lying here

Then show us what you do know. Remember, YOU claimed to have an aviation 'background' and 'study' and tried to use that to shut down the Indians. So show us what you do know.

One more time...

Q: What does asymmetrical thrust and yawing moment affects?

It does not look good for you, buddy.

See .. you are playing diverting again.
Remember how you loose in so many test and questions directed to you, and remember how you are busted at so many misconception that you have claimed.

And you are trying to conflict me with indian members and kissing their ars so that you keep getting supported and thanks from indian members?

And lose the fun? No problem here. Actually, the ones with the real problem are the Chinese crowd. This Indonesian suck-up is doing a terrible job at defending the J-20.

You have no mirror right?

You can get support from some indians and other russian/american members due to your kissing their ars, just like the above

 

[DrSomnath999]

You are simply equating China's military power with Serbia is again demonstrating your idiocy and fanboy mentality of old guy.

Serbia have no ability to blow down US' Satellites, nor can not screw US military information infrastructure.

sorry to spoil ur party mr chinese einstein ,but i couldnt resist myself.

but the biggest irony is SERBIA may be the only nation which has technically shot down an american stealth fighter F117 in kosovo war .

 

[UKBengali]

sorry to spoil ur party mr chinese einstein ,but i couldnt resist myself.

but the biggest irony is SERBIA may be the only nation which has technically shot down an american stealth fighter F117 in kosovo war .

And that did not stop Serbian infrastructure still being bombed to pieces.

Point remains that the US cannot bomb China without suffering serious damage itself.

China's air-defences are now very strong and it has a strong ability to strike US bases and ships out in the Ocean.

 

[antonius123]

sorry to spoil ur party mr chinese einstein ,but i couldnt resist myself.

but the biggest irony is SERBIA may be the only nation which has technically shot down an american stealth fighter F117 in kosovo war .

Really??

How do you know its due to the technology that Serbia poses?
How do you know China has no anti stealth radar technology?

Do you know the F-117 shot down in serbia mostly was because of the mistake that the Pilot of F-117 had made? and it is a very small probability occasion? It means in other F-117's sortie serbia may not be able to shoot down F-117 for the second time

 

[amalakas]

Really??

How do you know its due to the technology that Serbia poses?
How do you know China has no anti stealth radar technology?

Do you know the F-117 shot down in serbia mostly was because of the mistake that the Pilot of F-117 had made? and it is a very small probability occasion? It means in other F-117's sortie serbia may not be able to shoot down F-117 for the second time

another incoherent bubbling...

 

[sms]

Sorry to have missed your question pal

Your 1st question: Please let us know what does it use as material for nose cone

A: I dont know the classified ram data of J-20.

Your 2nd question: if this material is transparent EM wave how does J20 achieve LO capability? The flat plate (radar antenna and cockpit instruments) will result in huge reflection and detection at long range.

A: RAM is not a transparent EM wave material; in fact RAM commonly according to its name (Radar Absorbent Material) is a material that absorb EM wave. When radar impacts radar absorbent material, the energy acts as though it "sees" infinite free space instead of a boundary. The absorbed electromagnetic energy is dissipated as heat and very little energy is reflected.Therefore no such reflection from radar antena and anything behind the nose of J-20/Raptor.

Your 3rd question: Please advise how did Chinese engineers solved this problem and achieved a marvel gem of extreme engineering?

A: I dont know, as I have no connection with them.

Thanks, for your reply ...
But highlighted portion raises a big question about J20's capability to transmit it's own radar signals. How it's possible to do so if cone is not EMC transparent? If it blocks reflection it must block it's own transmission..does this mean J20 will go blind (without radar) in enemy territory?

Why are you ignoring my question... please reply at the earliest

Cone is semi transparent, some wave is passed some is reflected or absorbed by RAM.

But remember that the semi transparent here is not the same as what Gambit think which actually a misleading clueless concept. He thinks that semi transparent = absorbing

That is because you have no clue about the topic, thats why you cant answer

Now I'm confused your answer raises two questions.....

Scenario1 - Cone is semi transparent - it implies that nosecone (Radome) attenuates out going transmission/ reflection and incoming reflected signals from other aircraft/ object or incoming EM transmission from other aircraft/ land based radar.

It’s an ideal situation to avoid detection as J20 nosecone will be very effective to attenuate/ absorb in coming signal to avoid detection. But ..

It will do bad to it's own detection range as it will also attenuate out going transmission from its own radar and incoming reflected signals from other object. In layman's term it will impact J20's ability to effectively locate, track and engage targets at long ranges. It defies the whole idea of gen 5 aircrafts to locate targets at ranges without detected by others.

Scenario 2 - EM Transparent material..
There will be no attenuation for transmission from it’s own radar and no attenuation on reflected signals. SO it will be very good at detecting targets at range.

But, Transparent nosecone will expose it’s own radar (flat metal plate at least 1mtr dia) and other equipments on board beside radar and will result in lot reflection and will be easy to get detected. If detected at range it’s not gen-5 aircraft.


Please clarify how does J20 engineers strike a balance to get good LO and long search n track range.

Hi antonius123,
It's more than 4 months I'm still waiting for a reply from you. I'm not asking any tricky question as Gambit and gang is indulged but a simple query from a person with very low subject knowledge. I expect a better response and reply from you.

Thanks