Chengdu J-10 Multirole Fighter Air Craft News & Discussions

[Blacklight]

I will probably be off-topic a bit, but I found a very interesting canard design in J10. Most canard is symmetry section profile close to NACA00xx series, but J10 uses a complex twisted profile for canard. It seems it will generate lift at 0 AOA. Is it going to be more complex for aerodynamic design and FCS. What do you guys think? Does anyone know why they use this design?

@Socra Would be a good candidate to answer this question.

 

[Deino]

An interesting Tweet was posted today by @JeffHwang_EntH:

A rare evidence of J-10 naval version: wooden scaled model of J-10J.
I found it by accident on Zhihu, the author's father was a worker in CAC. This model was used in the demonstration, and was brought back to home as a keepsake after the project was cancelled.

https://twitter.com/x/status/1264792288330309633

 

[enroger]

I will probably be off-topic a bit, but I found a very interesting canard design in J10. Most canard is symmetry section profile close to NACA00xx series, but J10 uses a complex twisted profile for canard. It seems it will generate lift at 0 AOA. Is it going to be more complex for aerodynamic design and FCS. What do you guys think? Does anyone know why they use this design?

You got some good eyes... I'd love to know too.

 

[Scorpiooo]

An interesting Tweet was posted today by @JeffHwang_EntH:

https://twitter.com/x/status/1264792288330309633

Can i ask reason for canceling this J10J naval version, would have been a great addition with low frying cost

 

[serenity]

Can i ask reason for canceling this J10J naval version, would have been a great addition with low frying cost

Why buy last year's model car when you can buy next year's for same cost. Costs actually the same. We need to develop future generation fighters anyway so why buy 2x when you can just buy more capable fighter at start.

 

[LKJ86]

I will probably be off-topic a bit, but I found a very interesting canard design in J10. Most canard is symmetry section profile close to NACA00xx series, but J10 uses a complex twisted profile for canard. It seems it will generate lift at 0 AOA. Is it going to be more complex for aerodynamic design and FCS. What do you guys think? Does anyone know why they use this design?

The pics are from J-10B, and you can try to find some from J-10A/S.
CAC just tries to reduce J-10B/C's air drag and RCS.

J-10SH:

 

[laser911]

The pics are from J-10B, and you can try to find some from J-10A/S.
CAC just tries to reduce J-10B/C's air drag and RCS.

J-10SH:
View attachment 635444

We probably talking about different things. Yes. The antenna in front of the canard is an improved design in J10B/C. But I am talking about the wing profile, i.e. the section, of the canard. Your pic actually clearly shows the profile at root, and it is not symmetric (curved top and flat bottom). Most other canard fighters like rafale and eurofighter use symmetric profile which is curved top and bottom. Jas39 has a similar layout and root profile as J10 but it seems thicker than J10. But the tip is still symmetric. You can see the tip of J10's canard is even twisted to a double curved profile.

 

[Beast]

Can i ask reason for canceling this J10J naval version, would have been a great addition with low frying cost

Single engine naval J-10 is risky plus China never has any experience for naval ops during those times. But canard design is actually good for naval ops. Short take off and short landing. Which is why J-15 needs the canard.

 

[LKJ86]

J-10AH and J-10SH

 

[Deino]

And for the first time a PL-10 spotted on a naval J-10AH ... if I'm not mistaken on any Naval aircraft.

 

[enroger]

We probably talking about different things. Yes. The antenna in front of the canard is an improved design in J10B/C. But I am talking about the wing profile, i.e. the section, of the canard. Your pic actually clearly shows the profile at root, and it is not symmetric (curved top and flat bottom). Most other canard fighters like rafale and eurofighter use symmetric profile which is curved top and bottom. Jas39 has a similar layout and root profile as J10 but it seems thicker than J10. But the tip is still symmetric. You can see the tip of J10's canard is even twisted to a double curved profile.
View attachment 635450

I think J-10's canard is supposed to contribute lift in leveled flight, while the other design's (gripen/ef2000...) symmetric canards only provide control torque, does not contribute lift in leveled flight.

In zero canard deflection and zero AoA, J-10's canard shift both center of lift and aerodynamic center forward. Symmetric canards only shift aerodynamic center forward, does not effect center of lift.

I think it is only a minor design choice, J-10's canard produce more lift yet also produce downward draft downstream onto the main wings, so overall L/D might not differ. Just my two cents....

 

[laser911]

I think J-10's canard is supposed to contribute lift in leveled flight, while the other design's (gripen/ef2000...) symmetric canards only provide control torque, does not contribute lift in leveled flight.

In zero canard deflection and zero AoA, J-10's canard shift both center of lift and aerodynamic center forward. Symmetric canards only shift aerodynamic center forward, does not effect center of lift.

I think it is only a minor design choice, J-10's canard produce more lift yet also produce downward draft downstream onto the main wings, so overall L/D might not differ. Just my two cents....

If the overall L/D is the same or similar, whats the point of using such a complex design? It is going take more time to manufacture and increase costs. Also, I check most pic of J10 in air, the canard is at a slightly negative angle at most of time but positive AOA when gears and flaps down (ofc it is difficult to tell whats the actual AOA of canard from pic).

 

[enroger]

If the overall L/D is the same or similar, whats the point of using such a complex design? It is going take more time to manufacture and increase costs. Also, I check most pic of J10 in air, the canard is at a slightly negative angle at most of time but positive AOA when gears and flaps down (ofc it is difficult to tell whats the actual AOA of canard from pic).

For one it produces a more uniform lift distribution in the longitudinal axis, less stress on the airframe.

The canards must be positive AoA with respect to airstream in those pic you see, they are just negative deflect with respect to the plane. This is expected for a relaxed stability delta canard plane, the canards are still producing lift in those instances, the more AoA the plane is pulling the less lift from canards to keep the nose down.

 

[LKJ86]

J-10C

Via CCTV 7 and @沉默的山羊 from Weibo

 

[laser911]

For one it produces a more uniform lift distribution in the longitudinal axis, less stress on the airframe.

The canards must be positive AoA with respect to airstream in those pic you see, they are just negative deflect with respect to the plane. This is expected for a relaxed stability delta canard plane, the canards are still producing lift in those instances, the more AoA the plane is pulling the less lift from canards to keep the nose down.

So the plane will always try to pitch down? It sounds like a stable design as the center of gravity is in front of the lift center of the main wing. A disturb increases AOA will generate more lift on the main wings and push the nose down as the main wings always generate more lift than the canards. Am I right? I remember I saw a video of Rafael on level flight, the canards were clearly moving up and down(sure it was negative AoA).
Also, it seems the wingtip of J10's canards twist down a lot and it seems they are trying to reduce the downwash?
as seen in last post by LKJ86.

J-10C
View attachment 636117 View attachment 636118 View attachment 636119
Via CCTV 7 and @沉默的山羊 from Weibo