Russia Defence Forum

Would you like to react to this message? Create an account in a few clicks or log in to continue.

Military Forum for Russian and Global Defence Issues


    PAK DP prospective long-range interceptor

    LMFS
    LMFS

    Posts : 2766
    Points : 2768
    Join date : 2018-03-03

    PAK DP prospective long-range interceptor - Page 19 Empty Re: PAK DP prospective long-range interceptor

    Post  LMFS on Mon Nov 23, 2020 11:14 pm

    Backman wrote:Maybe this was discussed already.

    But is there any way that they could just somehow use a modified variant of the su 57 for this role ? The su 57 is such a good airframe.

    Maybe make a side by side cockpit for it. su 34 style.  Or just an in line 2 seater like the FGFA was supposed to be.

    Is the su 57 just plain too small for the role ?

    The Su-57 has some interceptor characteristics, but the PAK-DP seems to be a pretty extreme design that goes well beyond MiG-31 so yes, it seems not very well suited as it is for the kind of requirements that have been suggested.
    Backman
    Backman

    Posts : 257
    Points : 261
    Join date : 2020-11-11

    PAK DP prospective long-range interceptor - Page 19 Empty Re: PAK DP prospective long-range interceptor

    Post  Backman on Tue Nov 24, 2020 1:35 am

    GarryB wrote:Agree with KVS, the Su-57 design is not designed for top speed... it is designed for manouver performance... which is not really important to an interceptor, and stealth, which again is not important for an interceptor that will have an enormous radar operating most of the time to find targets and check airspace for threats.

    If they were going to base the MiG-41 on an existing design I would say the best choice would be the Tu-22M3 with much more powerful engines and larger internal weapons bay and a huge AESA nose mounted radar with the swing wings for low drag high speed flight... obviously made of different materials to take the heat at such speeds, but also with excellent range performance too...

    Perhaps a super cruising Tu-160P... 45 tons would be a lot of AAMs carried internally...

    Swing wings would be a natural for the Mig-41 yes. Cool and calm take-off and landing speeds. And sharp as an arrow when you let er rip. Plus the extra maintenance wouldn't be a big deal because the jet will always live at home.dunno  It wont be deployed to Syria or anything like that.

    It would be cool to see a new swing wing aircraft but the concept seems to be out of favor. I doubt we will see it.

    GarryB wrote
    For rather higher speeds I think a new shape in addition with new materials and new engines will be required and I suspect internal weapon carriage to reduce drag will be considered too.

    Modern digitally controlled variable intakes would go a long way.
    GarryB
    GarryB

    Posts : 27419
    Points : 27951
    Join date : 2010-03-30
    Location : New Zealand

    PAK DP prospective long-range interceptor - Page 19 Empty Re: PAK DP prospective long-range interceptor

    Post  GarryB on Tue Nov 24, 2020 2:58 pm

    Maybe this was discussed already.

    But is there any way that they could just somehow use a modified variant of the su 57 for this role ? The su 57 is such a good airframe.

    Maybe make a side by side cockpit for it. su 34 style. Or just an in line 2 seater like the FGFA was supposed to be.

    Is the su 57 just plain too small for the role ?

    The Su-57 is optimised for manouver performance as well as range and also stealth.

    The replacement for the MiG-31 needs speed above all else and flight range at enormous speed means it needs lots of fuel and a high speed efficient propulsion system.

    Su-57 is an excellent design, but simply not fast enough.

    Powerfull engines to light up a huge radar on the nose.

    Well that raises another issue I didn't consider... with turbojets idling at top speed with bypass air flowing through a ramjet to power the aircraft along at mach 4.2... then the MiG-41 is going to struggle to generate the electrical power needed to run a rather large AESA radar or three, not to mention other potential systems and bits of equipment...


    Swing wings would be a natural for the Mig-41 yes. Cool and calm take-off and landing speeds. And sharp as an arrow when you let er rip. Plus the extra maintenance wouldn't be a big deal because the jet will always live at home.dunno It wont be deployed to Syria or anything like that.

    It would be cool to see a new swing wing aircraft but the concept seems to be out of favor. I doubt we will see it.

    They have rebuilt a huge forge to make enormous titanium box structures for swing wing aircraft in the form of the Tu-160... it does not need to be identical or that size, but they could certainly make a large aircraft with swing wings.

    With a lifting body design as it gets faster and faster the need for "wing" lift would be smaller and smaller so a lifting body design with swing wings would be very interesting... especially if they could swing away completely straight back and offer very very low drag at top speed...

    I look forward to see what designs they could come up with.

    I remember in the 1980s I used to design all sorts of stuff with pencil and paper and one of my favourites based on the forward swept wing designs like the F-29 ( essentially a forward swept wing F-20), combined with my favourite aircraft of the time... the MiG-23... but with two widely spaced engines and a new lifting body with forward swept swing wings that can be angled from straight sideways for takeoff to sweeping forward till partially recessing into the fuselage and essentially creating a side fuselage chine like the SR-71 had and lifting body shape and thrust vectoring engines because it had no canards or horizontal tail surfaces... just a single vertical fin... it was not intended for manouver or high angle of attack flight....
    avatar
    Arrow

    Posts : 756
    Points : 756
    Join date : 2012-02-12

    PAK DP prospective long-range interceptor - Page 19 Empty Re: PAK DP prospective long-range interceptor

    Post  Arrow on Tue Nov 24, 2020 3:29 pm

    Interesting when the first flight of the MiG 41 airframe will take place. There is no information about the work progress.
    PapaDragon
    PapaDragon

    Posts : 9995
    Points : 10073
    Join date : 2015-04-26
    Location : Fort Evil, Serbia

    PAK DP prospective long-range interceptor - Page 19 Empty Re: PAK DP prospective long-range interceptor

    Post  PapaDragon on Tue Nov 24, 2020 8:44 pm

    Arrow wrote:Interesting when the first flight of the MiG 41 airframe will take place. There is no information about the work progress.

    Like with PAK-DA shape would clue in the competition on potential details so they will keep it on the down low until the last moment

    GarryB likes this post

    The-thing-next-door
    The-thing-next-door

    Posts : 899
    Points : 953
    Join date : 2017-09-18
    Location : Uranus

    PAK DP prospective long-range interceptor - Page 19 Empty Re: PAK DP prospective long-range interceptor

    Post  The-thing-next-door on Thu Nov 26, 2020 1:19 pm

    Were I tasked with designing a new interceptor I would rather focus on detection capabilities and weapons than increasing the speed, although breaking the sr71 record with a combat aircraft would be rather funny.

    I Would maintain the speed of the Mig-31 and design the aircraft around a very large internal weapons bay capable of carrying multiple Kinzhal sized weapons and some point defence missiles at the same time. The aircraft could use a lifting body to keep the width down to manageable levels and the thing could have multiple large radars giving it 360 degree coverage.

    So essentially a futurised Tu-128 with the Mig-31's speed.

    I do not really see the point in increasing the speed or maneuver performance any further than that of the Mig-31, they will need to build and operate a lot of these aircraft so expensive and unnecessary features like stealth and maneuverability should be dropped in favor of better reliability, longer service life and lower operating costs.
    LMFS
    LMFS

    Posts : 2766
    Points : 2768
    Join date : 2018-03-03

    PAK DP prospective long-range interceptor - Page 19 Empty Re: PAK DP prospective long-range interceptor

    Post  LMFS on Thu Nov 26, 2020 5:49 pm

    One of the most important roles that the PAK-DP could have is to act as a launcher of ASAT missiles or in general weapons capable of operating in near space, both against incoming HGV, space located ISR assets or ABM systems on orbit, which are going to proliferate massively in the next years since they are the only chance US has of actually countering the new strategic and sub-strategic Russian weapons. Therefore size, speed and ceiling would need to be increased compared to MiG-31, and who knows, maybe both MiGs stay in parallel operation for quite a few years, once they are modernizing the -31 further and producing its engines again. Probably it is no coincidence that the RTA engine capable of 4+ Mach was intended to power a launch vehicle.

    thegopnik likes this post

    GarryB
    GarryB

    Posts : 27419
    Points : 27951
    Join date : 2010-03-30
    Location : New Zealand

    PAK DP prospective long-range interceptor - Page 19 Empty Re: PAK DP prospective long-range interceptor

    Post  GarryB on Fri Nov 27, 2020 3:09 am

    Were I tasked with designing a new interceptor I would rather focus on detection capabilities and weapons than increasing the speed, although breaking the sr71 record with a combat aircraft would be rather funny.

    The faster the interceptor travels the further away from Russia the target will be intercepted.

    Get to them early enough in the North and those enemy aircraft might still be outside their cruise missile range of their targets in the south an west of Russia, which means when you shoot down 50 B-52s you will also be shooting down the cruise missiles they are still carrying...

    When a threat is detected the faster you can fly to it the sooner you can deal with that threat.

    I Would maintain the speed of the Mig-31 and design the aircraft around a very large internal weapons bay capable of carrying multiple Kinzhal sized weapons and some point defence missiles at the same time.

    Well the Navy will thank you but the Aerospace defence forces likely wont be as pleased... they would not have said mach 4.2 was the goal if they didn't think they could achieve it... or better it.

    The aircraft could use a lifting body to keep the width down to manageable levels and the thing could have multiple large radars giving it 360 degree coverage.

    They can build AWACS aircraft too... these interceptors don't need to do everything.

    So essentially a futurised Tu-128 with the Mig-31's speed.

    I do not really see the point in increasing the speed or maneuver performance any further than that of the Mig-31, they will need to build and operate a lot of these aircraft so expensive and unnecessary features like stealth and maneuverability should be dropped in favor of better reliability, longer service life and lower operating costs.

    The main reason they want to increase speed is because it would be easy... turbofans and turbojets don't like operating faster than about mach 2.5, but ramjets are only just getting started at such speeds and scramjets really don't have a top speed limit than you have to worry about (the rest of the aircraft will melt before the scramjet starts to struggle with speed in theory).

    You mention Kinzhal... Kinzhal is a solid rocket weapon... its flight parameters are fixed by the rocket motor... there is no throttle, and no variation in its burn rate... all you can change is the angle it is launched at and the altitude and speed it is launched at.

    When launched from the ground as an Iskander missile it is in the thickest air on the planet, so even when burning at full thrust the top speed of the rocket is limited. To maximise range and speed the first thing the rocket does is climb to get to the thinner colder air at high altitude where it can move faster and therefore further, so a lot of rocket fuel energy is used to climb and accelerate up to speed... it gets to mach 7 or 8 when it dives on the target... the advantage of climbing after launch is that some of the energy used to climb can be recovered when you descend again on the target.

    The problem is that energy is lost in heat and noise.

    The Iskander has a range of less than 500km because it burns energy climbing but it also burns energy manouvering as it approaches the target to evade interception by SAMs and AAMs.... which is why it was chosen as an air launched anti ship missile because it is already designed to fly high and fast and to evade air defence systems.

    The big thing of course is that when it is launched from a MiG-31K it will have flown 600-700km away from its airfield closer to its target, and more importantly instead of starting off still and in the thickest part of the atmosphere, it instead starts moving at about 2 times the speed of sound at an altitude likely to be 15-18km altitude... this means instead of using solid rocket fuel energy to lift its own weight and get moving all that energy goes into going even faster and climbing higher so it can climb to a higher altitude and it will be moving faster too, so it can fly much much further.

    The point is that if it was flying at mach 4.2 and at 30km altitude the same missile could probably travel 3,000km without any modification.

    If launched from the slower Tu-22M3 you have the opposite problem that its range would probably go down to 1,000km-1,500km because it will be launched at lower flight speeds and lower altitude... the Backfire has a service ceiling of 14km so it would probably launch at 10km altitude and mach 1.6 or so, but it could carry 4 of them which makes it still rather potent...

    The point is that new engines for much higher speed are being developed.

    If these new engines and new high temperature materials were not available the only thing you could do to it would be to make it longer ranged which means more fuel which just makes it bigger and heavier, but in this case what we are talking about is taking engines that are on the edge of what they can achieve in terms of flight speed, and to add propulsion systems at the start of their speed range limits at mach 4.2 with potential future capacity for much more.

    The extra speed will give existing weapons greater range and allow greater distances to be covered faster, and in terms of launching at targets in space it is a real boost in speed and likely altitude.

    It is like the question... why bother with Armata when you have upgraded T-90s... well because it is likely to be a completely new design of a new generation which is going to raise the bar and increase capability significantly...

    Sponsored content

    PAK DP prospective long-range interceptor - Page 19 Empty Re: PAK DP prospective long-range interceptor

    Post  Sponsored content


      Current date/time is Sun Jan 24, 2021 3:37 am