I’m not so sure about widespread CNT usage on airframes- especially not in the short term anyways. Although they have outstanding mechanical properties, including very high tensile strength, they aren’t as good at handling compressive forces as the nano structures get damaged, the bending and flexing of the wings and other aerofoils may result in buckling.

They may, however, have future roles in conjunction with ‘smart’ materials which dissipate loads such as adaptation effects in composites with controlled anisotropic elastic deformation properties.

You’ve half mentioned it in your 2nd post.

Having CNF infused into the resin acts as a mechanical bridge between the normal carbon fibre mat and the resin. This tends to dramatically improve manufacturability (reduced springback), damage tolerance (inc. impact damage) and most mechanical properties.

I don’t believe CNT in themselves will be used much. But instead CNF along with resin and traditional tow/weaved mat are pretty much at a point where they could be used now on flight research programs (such as where PAK-FA is).

Hmm… Makes me half-wish the PAK FA began development 5 years later. That stuff sounds like the future of aircraft construction, not just for engine blades but major aerostructure components.

Well, not so much CNT infused resins for composites but CNF (swap tube for fibre) infused resin.

It is being widely investigated, and has been getting a lot of attention for some time now – google CNF infused composite – its one of the reasons why I think A350, B787 and CSeries are a bit too premature – in 10 years time composite aerostructures will be* light years ahead of where they are today.

*should be – now most VLA OEMs (except Embraer) have vested interests in not moving too quickly.

It is quite possible Sukhoi are going to use CNF infused resins in the composites on PAK-FA. Indeed, I would be surprised if at least some components were not made using these resins (+fibres).

But… but…. but…. but…

It doesn’t have curved ducts…. it isn’t like the F-22….

IT CAN’T BE STEALTHY

[/stupid troll]

Good investigating Jō. 🙂

it’s highly doubtful that most pilots of the F-22 would be capable of flying these manoeuvres, without losing control of the aircraft.

With carefree handling, they should be able to replicate them pretty well. 🙂

Any and all comments welcome.

See that big object outside the window called the ground – never hit it too hard. 😀

Stick to that and ye’ll not go far wrong.

Just because a couple of machines arrive @ Lipetsk next year for state airframe performance trials, doesn’t mean it’s anywhere near operational capability- no matter how loudly the generals blow their trumpets.

I think you mis-understand me.

Unless changes are needed to the aerodynamic or structural aspects of the airframe – it is possible for machines that are rolling off the assembly line next year to be completely representative of machines that will be in the RuAF in 2020 (or whenever).

The only difference will be avionics, primarily software, some hardware.

It all depends on how their flight management systems are coupled to (or de-coupled from) their ‘weapon’ management systems and how open their system architecture is to allowing step updates in hardware.

RCS argument of one piece canopy is a load of BS.

It is well known that the canopy cannot be radar transparent as it would allow radar waves to reflect off the internal cockpit equipment – which will then produce multiple returns including corner reflections and scatter.

Therefore it must be absorbent and/or reflective. Then guess what – having a frame makes pretty much no difference (assuming your gap tolerances from canopy to frame are good).

Counter arguments are just the usual from clowns that think “it isn’t what was done on F-22, therefore it cannot be right”. :rolleyes: