S-70 "Okhotnik" UCAV

TVC is actually a good thing for a flying wing... if you have any familiarity with boats the angle of the propeller in a small boat is critical... when you start off it is angled down to lift the boat out of the water... once at speed and riding on the water you change the angle of the propeller because it not longer needs to lift the boat... the speed of the boat will hold it out of the water, so once you get up to speed you angle the propeller again so that it directs the thrust backwards which increases the speed of the boat because no energy is wasted trying to lift it any more.

With a modern flying wing it should have surfaces on the leading edge and trailing edge to change its level of lift... max lift for takeoff and landing, while minimum drag low lift for very high speed flight.

At different speeds different angles of thrust will improve performance and reduce drag.

At very high speed having the control surfaces in neutral means less drag but changing the angle of attack of the wing surface can also reduce drag too and a TVC engine should allow the aircraft to do that without adding the drag of a control surface deflection.

(Note the thrust angle is called trim...)

The problem I see with using TVC to correct for unneeded lift is that it's only one engine/nozzle, and one that's exactly inline with the longitudinal axis of the aircraft. A lot of force will be generated on afterburner and with a downward momentum, and under such conditions even a slight bit of turbulence underneath one of the wings can cause the aircraft to roll to one side because such an arrangement is not stable. And afterwards the UAV will careen out of control in a big spiral, as the TVC nozzle will still be inclined downwards, causing massive stress to the airframe.

The control surfaces on the wing still work and could keep the wing level... a single TVC nozzle really just changes the angle of attack of the engine thrust and can be used to pitch the nose up or down or yaw it left or right. With just one TVC nozzle the only thing it cant do is roll around its central axis which is critical for a dogfighter in a dogfight in a superstall with no airflow over the wings, but a near supersonic flying wing would have enormous roll control using its wing mounted control surfaces...

what's to stop them taking out SSGNs with kinetic velocity missiles ?

About 20-200m of water most of the time... water is very soft if you are gently lowered in to it, but when moving at speed it gets harder the faster you are moving and a hypersonic missile is moving faster than most...

this thing …. my money says
is a subsonic Su-57 flight control system ….. sans pilot … no after burners
but almost everything is carried over from the Su-57 ….

The information released suggests it is supersonic, plus afterburner would improve acceleration and altitude performance, which would be useful for missile launches... the higher and faster it is flying the longer the effective range of its missiles.

the tail even on an arrow is to make it obvious that the back is slower than the front

No, the tail feathers on an arrow is to keep the point forward by making the tail too high drag to turn around to the front.

the Russian air force chief is already on record as saying the new flying wing bomber will be subsonic and he also said there is very little reason to fly the Tu-160 supersonic either - as they were well advanced on hypersonic or near-hypersonic missiles with 6-7000 km range soon

This thread is about a UCAV, that is clearly based on the PAK FA and is designed to operate with it in combat.

The Russian air force chief is taking about a strategic bomber called PAK DA which has completely different requirements and will have a different design.

doesn't it seem that these flying wings all have really thick fronts to their wings ?

No.

The flying wing design that is the subject of this thread does not have a thick wing profile that suggests subsonic only flight.

The PAK DA probably will have a thick wing profile to have the internal volume to carry enough fuel and internal ordinance for strategic and theatre bombing missions, but this thread is about the S-70, which is a UCAV drone that will operate with the PAK FA.

is that optimal for supersonic flight ?

A Flying wing shape offers the minimum in drag for long endurance flight.

and yaw …. B2 from what I've seen seems to use split elevon type devices to slow a particular wing down
this doesn't sound a supersonic design to me …. they all seem to use that method

The B-2 is not a Russian design and is therefore a poor choice to highlight to indicate a potential Russian design.

so my conversation starter was/is …. what is thing meant for ? its big and subsonic
not for bombing jihadis ….. its not fast enough to cover big ocean distances quickly and it doesn't need to according to their air force boss
but it would be very useful for loitering along Russia's massive coastline …. as it is very low drag and stealthy
and the biggest threat are subs … SSGNs they all have 100+ cruise missiles onboard

It has been described as being a support drone intended to operate with Su-57 stealth aircraft... it can operate high and forward with sensors operating to detect targets and threats, or listening with radar for radar reflections from signals from Su-35 or Su-57s behind them scanning for threats.

Any targets found can be engaged using internally carried weapons so Russian fighters don't use up all their weapons dealing with incoming threats... a force multiplier...

kinetic weapons are solid tungsten rods …. they would go through water like butter ….
they have no warhead as their speed is the killer …. going at huge velocities
that's why I said kinetic ….. might work

As I mentioned, the funny thing about water is that the more energy you apply to it the harder it is... water does not compress... that is why it is used in hydraulics for lifting very heavy things.

Also the sea is big and by comparison a ship or sub is rather small.

you can argue with the head of the Russian air force that's fine by me ….

I doubt the head of the Russian Air Force gives a fuck about foreign SSBNs... well he might care, but it has nothing to do with his job... he is probably more interested in the 3,000 odd F-35s the americans say they are going to make... I am sure he is racking his brain to work out how he can make them build every single one of those and perhaps some more to bankrupt NATO....

aircraft are optimised for certain flight regimes - closely linked to the engines used

Totally agree here.

turboprops and propellers - move a lot of air a little bit … they fly best at 5-600 kts …. so almost every turboprop on Earth consequently has straight wings

True, except for the worlds fastest propeller driven aircraft, the Tu-95 Bear, which needs swept wings because of the speeds it can operate at require swept wings... but basically your point that turboprop designs are not expected to be supersonic is valid.

turbofan high bypass designs are optimal at high subsonic speeds .and surprise surprise every airliner on Earth has a wing optimised for that speed range about 30 degrees angle …. they all look the same now too

Agree... a high bypass jet engine trades volume of air for exhaust speed so gets high thrust but no good for supersonic flight speeds.

next turbojets and low bypass military jet engines are optimal for supersonic …. and most military jets are similar looking too ….
are you detecting a pattern yet ? wind tunnels do not change ….

Actually wind tunnels are designed for an enormous variety of aerodynamic shapes and engine types... the shape of the Tu-160 needs to be able to operate at the aircrafts top speed of mach 2, but it also has to take off and land at much much much lower speeds... in fact the landing speed of a Blackjack is almost always subsonic...

so here we have a flying wing design that is the same as all other USA and NATO designs …. and they are all high subsonic designs

Bullshit... the wing angle for this drone is exactly the same wing angle of the Su-57 sitting next to it... and the Su-57 is supersonic.

The only flying wing manned aircraft operating anywhere in the world at the moment is the B-2 and it does not have the same wing sweep angle that this drone has.

45 degree angles thick wings ….
your hypothesis is that somehow Russia is using the same basic universal design and they can by some miracle make it perform in a flight range that nobody else can ? it will go supersonic

This drone is not a strategic bomber like the B-2, it is a drone that is supposed to operate with the Su-57 in combat and that is the flight envelope it is supposed to operate within.

Modern fighters rarely spend very long periods at top speed because it dramatically reduces their flight range, but altitude and a supersonic flight speed does improve the flight performance of any missile fired so a high altitude drone that accelerates past the speed of sound to launch some R-77s or R-37s can get a decent reach with its AAMs without the Su-57 it is operating with needing to burn up fuel or use up its own weapons.

the reason they are using the engine from the Su-35 is it currently available and it is already used in an Su-57 control system
its called expedience and practicality

If you are correct and it is a subsonic long range PAK DA replacement then why the fuck is it so small... what other countries have strategic bombers smaller than a Flanker?

Why isn't its engine a high bypass turbofan like a PD-35 or something equivalent?

Why a medium bypass turbofan with powerful afterburner?

this Okhotnik won't be built for minimum 4-5 yrs … by then the Su-57 will have the more compact and variable cycle Iz-whatever-30 ….
it will be built in mass production with that engine …

The first Su-57s are already built and in the future will likely change engine a couple of times and it will be the same for any drone designed to operate with it.

most current USA UAVs use high bypass civil and military designs …. some even from business jets
Russia doesn't have engines like that right now …

If the drone is going to operate with the Su-57s then it makes sense not to develop a whole new engine class for it... just put whatever the Su-57 is using at the time into it.

you can nitpick every single word I say as you always do …. I'm talking about a huge body of aerodynamic evidence that says this flyingwing will fly just like the others …. just like all the wings on turboprops look the same … just as all the jet airliners look the same … etc etc

I think if you look at a turboprop like a C-130 or An-12 and a turbofan like a 737 or whatever you will see the Turboprop aircraft have straight wings... the exception is the Bear and Bear related aircraft like the Tu-116 and Tu-126 which also have swept wings because of their top speeds require swept wings... just like jet airliners with turbofans.

What I don't understand is WTF turboprops has anything to do with the Su-57, the S-70 drone or the PAK DA strategic flying wing...

my vote says …. the air in wind tunnels in Russia is no different to the air in France or the USA …
I'm a pragmatic realist

And if they were the same why would the Europeans want to use Russian wind tunnels?

I would also point out that the Russians and Soviets have used wind tunnels for testing cars and ships at low speeds right up to rockets and hypersonic missiles and aircraft shapes... and I can tell you there is more than one wind tunnel at the TsAgi in Russia...

The initial info you refer to are coming from an official source?

PiBo doesn't normally make things up...

to break the air defense (PVO) when paired with a fifth generation fighter, the su-57.

So for instance it might be loaded up with long range AAMs and ARMs and could be sent forward operating at high altitude with the purpose of getting the enemy air defence to light up... it can start taking down major radar and SAMs and any aircraft that gets airborne while transmitting radar and IRST information to the fighters it is operating with...

I doubt it will be a supersonic supercruising aircraft but it might be capable of achieving supersonic dash for a limited time....I've seen speculation it will be able to achieve a speed of 1400km/h at low altitude...which would be pretty impressive....but lets see which way things develop. It's too early still

Actually I disagree... top speed is not about power to weight ratio, and it is not about being super light... top speed is about low drag and high engine thrust with a high speed engine exhaust speed... the MiG-31 has a much lower power to weight ration compared with modern fighters but is much faster.

If you want very high altitude flight then an enormous thin wing and very light weight will get you there in a sail plane and a very fast aircraft might be another way of getting there... certainly a flying wing will have the best lift/drag ratio, the lowest overall drag and the lowest wing loading... with a modern 5th gen fighters turbojet engine or low bypass turbofan you get a hot high speed engine exhaust for high speed and high altitude flight...

That picture is interesting because of all the weapons on the ground next to the drone and all the fighters seem to have external weapons fitted... except the Su-57 of course... makes me think that this was a staged setup for a guest to come and look at rather than operational testing of all the aircraft fully armed... someone was coming to inspect the troops...