Su-47 Berkut and MiG 1.44

secretprojects wrote:

kvs wrote:Funny how the people who literally wrote the book on stealth (i.e. the mathematics based on the physics) are supposedly
unable to design stealth aircraft.   Westerners should listen to themselves talk, you sure sound like chauvinist retards.

The F-35 is an example of the inanity that permeates western "thought".   For the longest time we had whining fanbois
piss all over the place about how circular nacelles defeat stealth.   Yet for the F-35 they are fine.   No, you fanboi clowns
do not get to conveniently forget your retarded spew.

Presumably you mean Pyotr Ufimtsev. His treatise was a very technical one on a way to calculate one class of radar reflections in a specific use case which was highly useful to Lockheed engineers when calculating the RCS of their faceted aircraft designs. This is not in any way like 'writing the book on stealth'. 

GarryB wrote:The design influence is pretty clear, but I would suggest the contents of the MiG was basic and not yet developed, so likely the contents of the Chinese model wont be as good as a MiG PAK FA could have been if also funded.

Essentially I would expect the Chinese probably got a bit of design assistance from MiG, which likely speeded up the development of the physical external shape and aerodynamics, but I think the engines and avionics are probably not up to 5th gen levels yet.

If they had 5th gen bits to put in this aircraft then they would also be putting those same bits in Su-27s and not need to buy Su-35s.

I am not dissing the Chinese in this regard... Europe doesn't have a 5th gen fighter either.

kvs wrote:China should get some credit.   They are likely to have fully researched the problem and produced sufficiently advanced modeling
software to be able to test the EM interaction characteristics of their stealth jet prototypes.  

In many ways, modeling the stealth characteristics of jets is easier than figuring out the metallurgy of jet engine turbines.
Some things come from long term experience.

Backman wrote:
If they are making mistakes like this on the civil side, then I dont think China will be passing Russia in aviation anytime soon. But a lot of ppl in the west cant see this

GarryB wrote:When you design something the very first thing you do is look at the problem and then look at existing solutions to the problem.

A case in point is the American Space Shuttle.

When the Soviets got the task of designing their own they could have started testing all sorts of far out designs and they might have... but they knew NASA spent 2 billion dollars refining the design they chose, which they chose based on materials and design capability at the time to be the best they could possibly make it.

The Soviets would be idiots to ignore the US space shuttle design, but what likely happened was that they split into groups with one group getting the US design as a basis and the others having to come up with unique designs.

It means there is a chance you might get a better design but you have as good as the american engineers could manage with their super computers and advanced models etc etc.

In the end the external shape of the Buran was very similar to the US design... there was no point in spending billions of dollars on trying to make something different... what was important was to make something better and if it couldn't be better then the same is good enough.

The real irony is that many westerners look at the Buran and think copy.

Fundamentally it is a different type of craft.

Think of the US Space Shuttle as being a C-130 transport aircraft with its own engines... it is a rocket in its own right.

The problem is that its size and weight means it needs an enormous fuel tank bigger than the whole aircraft itself to carry enough fuel to get into space and when that huge fuel tank is fitted it is too heavy for its own engines to move it let alone take off, so a couple of enormous solid rockets are attached like giant RATO or JATO bottles to get the whole thing moving.

Problems with that include once the solid rocket motors are lit you can't throttle them or shut them down... they are enormously expensive, and can't be reused.

Having the liquid rocket engines in the shuttle itself means they are dead weight for the flight... about 10 tons of dead weight you carry everywhere.

The payload capacity of the shuttle is about 10-20 tons and is pretty much limited to the cargo bay on the shuttle in terms of physical dimensions... OK for deploying or recovering a satellite but not great for space station construction.

The Buran on the other hand is totally different... it has no big powerful liquid rocket engines, which means it can carry more payload... the all up weight of the Buran was 105 tons. That includes a payload capacity of 30 tons. The numbers for the US SS are harder to come by but from what I can find it is 120 tons for the Shuttle but not the external fuel tank and solid rocket boosters with a 20 ton payload (actually 18 tons).

The fundamental difference is that Buran is a glider... it sits on an Energya rocket and is blasted off into space on the back of a missile.

If you are launching satellites or recovering them Buran can do that, but if you are building a space station you can take the Buran off and put a 120 ton payload on the back of the Energya and build your space station much much faster... the current ISS weighs about 350 tons so four or five missions could take up all the bits and pieces needed... assembling stuff in space is a pain in the ass so having complete modules you can simply link together and perhaps one launch with all your solar panels in a big flat pack that folds out on command would be a much quicker and much cheaper and much safer way to build a space station.

The Space shuttle is not terrible, it led the way but the idea that reusing it would lead to it being used a lot and therefore become cheaper never panned out.

GarryB wrote:So is that because the 1.42 had secret shaping and details they didn't want to reveal with the prototype but would be needed on the final aircraft to make it stealthy, or was it just a code thing... 1.44 is the development airframe and when ready for serial production it is renamed 1.42?

LMFS wrote:

GarryB wrote:So is that because the 1.42 had secret shaping and details they didn't want to reveal with the prototype but would be needed on the final aircraft to make it stealthy, or was it just a code thing... 1.44 is the development airframe and when ready for serial production it is renamed 1.42?

My understanding is that they were actually different, you see the new intakes and the cranked delta wing, for instance. I think this aero layout has not been yet surpassed...

magnumcromagnon wrote:Do you think the design could adapted to PAK-DP?

GarryB wrote:I have never really been a huge fan of canards.

marcellogo wrote:
 Canards are not a stand alone thing, so when they come coupled with a pure delta wing, they are the real deal but when they are put on a plane that already has a conventional tail they became just a way to correct some design imbalance.

So probably they used the 1.44 and the 1,42 as a proof of concept to evaluate the whole idea of a canard delta but in the end they decided to keep on with their own trademark blended wing/podded engine  design and they had 100% reason into doing it as both the success of the 4+ and 4++ version of Flanker and the development of Su-57 have clearly demonstrated.
Now, they come with an added bonus as LEVCON developed with the Su-57 program + TVC engines would allow to have a viable alternative to canards themselves on future deltas also.

LMFS wrote:

marcellogo wrote:
So probably they used the 1.44 and the 1,42 as a proof of concept to evaluate the whole idea of a canard delta but in the end they decided to keep on with their own trademark blended wing/podded engine  design and they had 100% reason into doing it as both the success of the 4+ and 4++ version of Flanker and the development of Su-57 have clearly demonstrated.
Now, they come with an added bonus as LEVCON developed with the Su-57 program + TVC engines would allow to have a viable alternative to canards themselves on future deltas also.

The demonstrator and the definitive model should not be a proof of concept of exactly the opposite idea to that you want to implement...

MiG's approach was clear, then MFI got axed then Sukhoi came up with a different layout. The biggest advantage of their approach is bigger bays space and maybe better stealth, aerodynamically I don't think it is superior. For instance the LEVCONS fulfil in the PAK-FA the roles of helping attach the airflow to the wing at high AoA (not as well as the canard there) and minor trim adjustments, it does not deflect upwards and so does not help pitching the nose up. The more compact placement of the engines close to each other has also some good advantages vs. the podded design, like smaller roll moment, friction + interference drag and weight.