F-35 vs Su-30/35

The F-35 compared with other modern jets.
User avatar
Forum Veteran
Forum Veteran
 
Posts: 883
Joined: 10 Feb 2014, 02:46

by geforcerfx » 13 Apr 2015, 09:16

eloise wrote:"Airframe generally similar to the Su-27, but when create the su-35 used a new aluminum-lithium alloys, greatly expanded the use of composite materials. "

they said they expand the use of composite materials, but it doesn't say, they do it at the surface , it is likely that new composite materials is only for internal part, the truth is things that contribute greatly to high RCS on su-27 such as intake, engine fan blade, vertical stablizer, pylon, wing stay exactly the same on Su-35, same shapeand they didn't change the shape or materials for these part[/quote]

Well I found this

"The engine gives the Su-35 limited supercruise capability, or sustained supersonic speed without the use of afterburners.[47] Radar-absorbent material is applied to the engine inlets and the front stages of the engine compressor to halve the Su-35's frontal radar cross-section (RCS); the canopy was also modified to deflect radar waves.[48]"

on Wikipedia (whoop) with some articles linked, I thought I remembered seeing the Su-35 had S-Ducts but they have some kind of RAM applied to the engine, somehow. Prob still not half the Su-27 but I would venture a guess the Su-35 is definitely not the exact same signature as the Su-27, the real question is do they keep up on the ram maintenance on the Su-35.

sergei wrote:
"what about cruising speed? not faster than F-35 i bet"
If my memory serves me something like 0.85m+ for F35 and 1.01 for Su-35


I call BS on that, if i remember correctly 1.1 or 1.2 was achieved when the aircraft was clean, if you have 8 A2A missiles hanging off that thing its cruise will be .95 for any flight planning on lasting longer then 30 min. The F-35 cruise speed depends on mission profile it can do as low as .75 for CAS and strike for maximum fuel efficiency or up to 1.2-1.3 for 150nm for "efficient" dash speed.

At the end of all this data there is two glaring things sticking out the flanker and F-35 are different classes of fighter jets, the F-22 vs Su-35 debates are much more relevant since we are talking two air superiority platforms (as much as the Russians wish the Su-35 was multi-role it's limited). The F-35 has some advantages in technology, avionics, sensors, radar (gonna give it to the F-35), the Su-35 is the better kinematic platform, thought I think both the F-35 and the Su-35 would have fantastic ranges looking at there fuel margins.

But the real question at the end of all of this is not can a single F-35 beat a Single Su-35. But can the 100(who knows maybe 200) SU-35's that Russia would like to buy be able to take on 300-800 F-35's(only half the USAF projected force)? That's really the question, does the advantages the Su-35 leverage over the F-35 give it enough capability to take on 4 to 1 odds against the F-35? Personally me thinks not. :D


Enthusiast
Enthusiast
 
Posts: 84
Joined: 25 Mar 2015, 15:38

by ata » 13 Apr 2015, 10:14

Ok can you give me a an exact source that said the radar signal at the target is several thousand times stronger than reflected signal? because that simply doesn't fit the radar equation at all
secondly, as i have explained, RWR have trouble detect LPI radar not because it doesn't detect the radar signal, or that the radar signal lower than the noise level, but because the LPI signal have little to zero characteristics for RWR to separate it from background noise ( remember the background noise level are not the same all the time so you cant just classified all signal above a certain level is radar signal)
read the part about compression of pulse in the slide i gave you


I'll answer this first, because all the rest will take even more time.
The source of my statement again simply is physics. Let me explain you some basic theory. I'm sorry in advance if it sounds arrogantly.
In our case any antenna we can present as master oscillator. The main characteristic of ANY antenna in the world will be it's GAIN. For example aperture is absolutely unimportant because aperture in general only define gain. You can create huge aperture antenna, but if it's gain will be low, then such a size just useless. So, what in fact gain means? Frankly speaking it's how wide or thin antenna's beam. Of course it's not a definition (there are lobes, losses etc), but it's enough to understand the idea.
Look at this: http://www.aktivsb.ru/article-info1499.html
Compare left and right patterns at first picture. At right side antenna has very low gain because it transmit power to whole world in front direction. At the left side gain is much higher because it only sends signals in one thin beam (skip the lobes at the moment). All the power just in one point. Why is it important? Because in case of radar: LPI, non-LPI, no matter what engineers try to create the thinest reasonable beam possible. To bring all the available power in one point.
Do you remember I've calculated that at 100 km 2 degrees beam will give you 3,5 km spot? It's not exactly truth. It will be even bigger, but normally this kind of sizes measured at -3db, -10 db levels (it's all depend of agreement and standards). That size's spot will be about 10 sq. km. while Flanker size object (not it RCS) actual size will be about 10 sq. m. So only 1/1 million part of your energy will make sense. All the rest you spent to heat up atmosphere.
The another theory. What electro-magnetic reflection means? Again, frankly speaking incoming wave generates some electric current in metal shape, and that current generates electro-magnetic field in back (this is very simplified theory, because for example dielectric materials also reflect some radio waves). In fact your target acts like secondary oscillator. The only difference it will transmit it's power in every direction. Let's say in every direction in the same level. Let's calculate how big is your radar (1 m in diameter) from 100 km far away for antenna with 0 db gain.
Approximately it will be 1/4*10ˆ-11
We also have to remember about initial 1/1 million part of energy. Finally you'll get 1/4*10ˆ-17. It's -164 dB. While at target side it's just -80 dB (because Flanker's radar has approximately 1 sq. m size as well). About 80 dB difference.
Wow, isn't it? In fact because I simplified the idea (to show the origin of such high loss) it's not exactly correct. Look at this: http://www.radartutorial.eu/01.basics/T ... on.en.html
Function (9) shows that received power is 1/Rˆ4 function (because antenna gain, RCS, transmitted power are constants). Even if you have 40 db antenna gain (which seems not really possible) and squared it's just 10ˆ8. If you have relatively high RSC it's another 10ˆ1. Even in that case it will be still 10ˆ-11 of transmitted power. While at target side it will be 10ˆ-5.
So, Flanker radar operates in fact not thousands, but million times higher signal level than that at F-35. So, if F-35 is able to detect it's signal from the noise why do you think it's a problem to do with million times better option (noise level is the same for both sides)? Yes LPI switches frequencies, but it's not like "from any to any" those peaks are still in X-band. And because Flanker radar is also X-band it will receive all of them. We can talk about fighting with the noise but believe me dealing with noise is huge part of radio tech and I need to take all my old books from the shelf to remember all the stuff. It's well known problem and it's discovered from the first phone-line in the world.
If you have any application to generate spectrograms for sound files try to do the following. Generate the file with several very short peaks with different frequencies. It will emulate LPI. Then apply some noise (it's possible with apps like SoundForge). Even you can do noise level similar to peaks level. Then generate spectrogram. It should look like this: http://audiophilesoft.ru/articles/quali ... fhg320.jpg
At your picture you'll see small bright dots - these are your peaks. If you can see it with your eyes, then it's possible to create algorithm to detect it. This is how LPI works.


Enthusiast
Enthusiast
 
Posts: 84
Joined: 25 Mar 2015, 15:38

by ata » 13 Apr 2015, 11:18

eloise,

let's continue...

1) i gave you the USAF claim for F-35 RCS, which is around 0.0015 m2

2) when you complain that F-35 will only have low RCS from very narrow frontal angle, i gave you F-117 average frontal RCS that they measured in Have Blue program, which is around 0.001 m2 within 45 degree frontal

3) i also gave you the simulation of YF-23 radar scattering characteristics without RAM, sure it a bigger aircraft than f-35 but they are both stealth fighter with somewhat similar shape, btw in the pictures RCS was measured in dBsm
so i dont really understand what you mean by not enough number?


and

someone else already posted information related to engine fan blocker in F-135 and F-119 engine above ( have a look ) , there was info about LOAN nozzle as well
also i dont really think you can see the engine fan from wide angle


So, please check this picture:
Image

What is the angle of the shot?

And here:
Image

And here:
Image

And here:
Image

So, the angle I would say about 30 degrees at max. If not 45.
This is what I mean, add here "side view" and "from the top and bottom" -> RCS ALWAYS needs to be indicated at min at max value. At least at tactically meaningful directions. Front direction doesn't make us able to make any conclusion.
F-117 is an ottoman with wings and powerful engine. It even has no radar at all (which we remember is very important from RCS point of view), and even that "all in the name of stealthy" was downed when it touched more or less effective SAM. So, it's not a good reference point.
And "similar shape" is perfect. All the aircrafts have more or less similar shape. Body, tail, wings.... Sorry, I'm joking. In fact, as I said it's incredibly hard to know in advance which parts of the body will affect RCS and which will not. Even it's quite useless to model "metal body" because main impact caused by internal parts, of something sticks out from the body (like EOTS).

Also

i dont quite understand what you trying to say, can you draw a picture or something ? , if you are trying to say you will spread su-35 formation apart so that they will see F-35 from angle wider than 45 degree each side and F-35 can't turn it's nose to them, then the Su-35 must be very very far apart from each other , for example if the distance between f-35 and su-35 is 100 km then to be able to see F-35 from angle of 45 degree then the su-35 must be about 200 km from the other
http://www.cleavebooks.co.uk/scol/calrtri.htm


I'm not quite good at drawing. Well.... I'm really bad at that. Anyway: http://flockdraw.com/gallery/view/2020723
So, of course F-35 can turn... but we're talking about distances like 100-150 km, which means Flanker already knows that F-35 in that direction and even if it disappeared from radar it will take 10-20 seconds to reach the range where it will appear again. Of course F-35 can attack at that time, but it will be using radar in that case, and we already discussed it mean the same as F-35 is not stealthy at that time.


Enthusiast
Enthusiast
 
Posts: 84
Joined: 25 Mar 2015, 15:38

by ata » 13 Apr 2015, 11:35

But the real question at the end of all of this is not can a single F-35 beat a Single Su-35. But can the 100(who knows maybe 200) SU-35's that Russia would like to buy be able to take on 300-800 F-35's(only half the USAF projected force)? That's really the question, does the advantages the Su-35 leverage over the F-35 give it enough capability to take on 4 to 1 odds against the F-35? Personally me thinks not.


You should add here Mig-31 (about 200 units) and plenty of old Su-27 (almost 400), Mig-29 (250) which are still excellent as simple missile carriers (just need support from better radar equipped units). But as I said earlier, in real situation main enemy of F-35 would be not Su-35, or Su-27 and even not a Mig-31, but S-300/400 which doesn't care of stealth at all, it's able to detect them all as soon as they get up from horizon. And because in new versions it's able to down planes from 400 km.... well, it's not that obvious.
That's why we're talking about F-35 vs Su-35 face to face.


Active Member
Active Member
 
Posts: 151
Joined: 02 Mar 2011, 13:40
Location: Dublin

by shrimpman » 13 Apr 2015, 11:55

You created a lot of questions in my head, Ata :) America is still asleep, I will keep close attention to what they are going to say. Sorry for my uneducated opinion, but there is something I cannot understand. Ever since I have found this website and started to get familiar with the forum contents, I got a very clear image, that the biggest word, bar none, in military aviation nowadays is AESA. You say PESA can be just as powerful, or even stronger. Your calculations make sense, but I’m no physicist, gotta wait for Americans to wake up and brew up a reply. What bothers me is that I find it very hard to believe PESA would really be that effective. As far as I can speculate, Su-27 family is most closely resembling American F-15 in performance, radar size and role. And yet PESA equipped F-15’s are a duck soup against stealthy F-22. The only instance F-22 AESA radar was even detected was by F-35 as someone mentioned already couple weeks ago. Immediate assumption is that targeting F-35 would be a very challenging task as well, while F-35 LPI radar would have little trouble seeing non-stealthy objects at long distances. If a couple of AMRAAMS hanging on the external hardpoints makes the F-35 quite easy to detect, then I would assume a Flanker armed with its 10 AA missiles would lit up like a Christmas tree even when hit with a relatively weak beam. Am I badly wrong here? I’m sorry to doubt your point, but it’s quite hard for me to grasp that idea. It feels a little bit like reading history books about pre-WWII generals arguing that all-metal monoplanes were a ridiculous idea and that bi-planes were the way to go. Or your own marshal Budionny, who claimed in 1937 (IIRC) that tanks will never replace cavalry.


Enthusiast
Enthusiast
 
Posts: 84
Joined: 25 Mar 2015, 15:38

by ata » 13 Apr 2015, 12:26

shrimpman wrote:You created a lot of questions in my head, Ata :) America is still asleep, I will keep close attention to what they are going to say. Sorry for my uneducated opinion, but there is something I cannot understand. Ever since I have found this website and started to get familiar with the forum contents, I got a very clear image, that the biggest word, bar none, in military aviation nowadays is AESA. You say PESA can be just as powerful, or even stronger. Your calculations make sense, but I’m no physicist, gotta wait for Americans to wake up and brew up a reply. What bothers me is that I find it very hard to believe PESA would really be that effective. As far as I can speculate, Su-27 family is most closely resembling American F-15 in performance, radar size and role. And yet PESA equipped F-15’s are a duck soup against stealthy F-22. The only instance F-22 AESA radar was even detected was by F-35 as someone mentioned already couple weeks ago. Immediate assumption is that targeting F-35 would be a very challenging task as well, while F-35 LPI radar would have little trouble seeing non-stealthy objects at long distances. If a couple of AMRAAMS hanging on the external hardpoints makes the F-35 quite easy to detect, then I would assume a Flanker armed with its 10 AA missiles would lit up like a Christmas tree even when hit with a relatively weak beam. Am I badly wrong here? I’m sorry to doubt your point, but it’s quite hard for me to grasp that idea. It feels a little bit like reading history books about pre-WWII generals arguing that all-metal monoplanes were a ridiculous idea and that bi-planes were the way to go. Or your own marshal Budionny, who claimed in 1937 (IIRC) that tanks will never replace cavalry.


Well, these are good questions, actually. And, if you ask my opinion, I would say AESA is much better than PESA. Again, more power doesn't mean PESA is better. When I answered about PESA I only mentioned the statement AESA is more powerful. There are many limitations PESA technology has. So, of course if you can choose, then AESA is a best choice. BUT. If you need simply max detection range, then PESA will be (in general (!)) better then AESA. Point here is that brightest torch is not always better option. It all depends of situation.
About that statement F-22 radar was only detected by F-35. What is source, first of all? I'd like also to know more about conditions. Of course LPI makes sense. In equal conditions if you transmit less power you're less visible. It's obvious. So, maybe F-15 simply has no that algorithm as I mentioned to process many small peaks. BTW I'm not sure if Flanker is able to do that, I only said it's possible in theory. Maybe something else was different from our "ideal situation", I don't know. I only want to say LPI as well as "stealth" is not something magical, and it required details to be applied to any tactical modelling.
Last edited by ata on 13 Apr 2015, 14:31, edited 1 time in total.


Enthusiast
Enthusiast
 
Posts: 84
Joined: 25 Mar 2015, 15:38

by ata » 13 Apr 2015, 14:19

ok, eloise, let's continue

look at F-22 and F-35 canopy, they are not completely transparent are they? , that is because they are coated with really thin layer of gold to prevent the radar wave from entering the cockpit, they are also designed to be able to reflected radar wave away from the source, same with EOTS
btw F-22 was meant to have similar thing to EOTS but there wasnt enough funding and it was meant to be air superiority fighter only so that part was cut.
Also the radome of F-22, F-35 was coated with some sort of bypass RAM that only allow a certain frequently go in and out, the radar was also canted to reflect enemy radar wave aways other than back to the source


I know for both F-22 and F-35 there are a lot of efforts to decrease canopy/pilot impact to RCS, but thin layer of gold, from my understanding is simply works as a mirror for optical range. If you put piece of mirror in the sky and will light it with a torch, in case of right angle it's will be invisible, because all the torch power will be reflected out from you. I guess it the same with gold coating for radio waves. But if only that mirror in the sky will be curved and you'll get appropriate angle you'll see very bright spot. I agree, in real life if F-22 or F-35 are high in the sky you likely can never see canopy at all. But you will see EOTS in that case.
Bypass RAM is useless to discuss in this case, because both radars operate in the same band, so it simply transparent for Flanker radar. And what do you mean for "the radar was also canted to reflect enemy radar wave" - if radome is transparent, then it can reflect nothing. As far as I know this is a reason why radar is slightly angled in dome (in addition it gives lower aperture so, it's better for aerodynamic). But again, if Flanker is higher than F-35 then it may get directly at 90 degrees to F-35's radar plane.


Enthusiast
Enthusiast
 
Posts: 84
Joined: 25 Mar 2015, 15:38

by ata » 13 Apr 2015, 14:28

Top speed of Su-35 is higher than F-35 in clean configuration, what is it top speed when it fully loaded with 10-12 AAM? , what about cruising speed? not faster than F-35 i bet, also since F-35 detect Su-35 much earlier than Su-35 can detect F-35, thus it will have much longer time to accelerate to high speed, altitude to give it's missiles more energy if necessary

Range? : ok, i think Su-35 have better range

Radar? : in theory, if F-35 and Su-35 producers both have access to same level of funding and technology then the su-35 radar should be better because it is bigger, However in reality F-35 program have much higher funding and arguably better technology, as a result it was equipped with modern AESA with really good LPI characteristics, by contrast Su-35 only equipped with PESA radar,
while i still think Irbis-e have better range than APG-81, according to some one else calculatiom here, that may not be the truth
=> APG-81 have better LPI than Irbis-e, which one have better range performance is still to be discussed

Maneuverability : in theory due to TVC su-35 will have better max turn rate, lower wing loading will likely give it better sustain turn performance at high altitude , by contrast F-35 high wing loading will give it better roll rate, dive rate, sustain turn ability at low altitude,
su-27 with 4 AAM have much worse acceleration rate compared to F-16 with similar load out, Su-35 have better engine but it also quite a bit heavier, if you want to load it with 10 AAM do you really think it will out accelerate F-35 with 4-6 internal AAM? i dont think so

Armaments : i really don't see R-77 and R-27 have any advantage over Aim-120D or Meteor, CUDA


Su-35 vs F-35 dynamics I'll leave to sergei, he's much better than me in this part
This was only to answer your statement that we can't trust Sukhoi as well as to LM. My idea is that Sukhoi statements are about things that a proved for a long time. Of course it's a point of discussion how effective Su-35 RAM coating for exaample. And I'll easily believe if you can find info or ideas why it's not that good. Because Su-35 "stealth" option is just an option. If they can do that, then why not? If it works, perfect, if not... then all the rest of advantages are still here.
In opposite, I've provided many reasons why stealth, LPI, EOTS are not that effective as LM wants us to believe.


Forum Veteran
Forum Veteran
 
Posts: 850
Joined: 15 Oct 2009, 18:43
Location: Australia

by mk82 » 13 Apr 2015, 17:57

ata:

"So, of course F-35 can turn... but we're talking about distances like 100-150 km, which means Flanker already knows that F-35 in that direction and even if it disappeared from radar it will take 10-20 seconds to reach the range where it will appear again. Of course F-35 can attack at that time, but it will be using radar in that case, and we already discussed it mean the same as F-35 is not stealthy at that time."

Hang on a minute ata, a few glaring points:

1. You are assuming that the SU 35 will always have VHF radars to point them in the general direction of the enemy. In a shooting war, those VHF radars will be prime targets or suppressed ruthlessly. Good luck with SU 35s knowing where to look for F35s in the first place without the aid of long wavelength radars. That comes directly to my second point

2. I don't think the SU 35 radars will be detecting fully stealthed up F35s (internal carriage only) at 100 to 150kms. You even admitted that. I definitely don't think flying for 10 to 20 seconds more is going to improve the SU 35's chances of detecting the F35....the SU 35s will most definitely be using it's afterburners...it's IR signature will be similar to the sun (on IRST) and it still has a relative RCS of a barn....the SU 35s will simply be eating AMRAAMs in the face 10 to 20 seconds later.

3. I have never heard of the SU 35's EW system/RWR being able to detect LPI signals. You even admitted that! Lets stick to what the SU 35 can currently do rather than your theories. So a few F35s painting the SU 35s in LPI mode will not tipping off the Flankers that they are soon to be flying burning wrecks.

Actually, why don't we compare the PAK FA to the SU 35. If Tikhomirov (no doubt some smart guys work there) manages to create good LPI modes for the N036 AESA radar, I would love to see the results of mock engagements between the PAK FA and the SU 35...actually, I can tell you now, total slaughter of the SU 35 force, they will detect the PAK FAs much later and potentially have no idea that the PAK FAs have been painting them with radar period. If you haven't tweaked on to why the PAK FA will hammer the SU 35s, it is not because it flies faster or is more maneuverable, it's because it has much lower RCS, potentially harder to detect radar emissions and can potentially fight smarter if it has good networking capabilities. Qualities that the F35 will have.

Frankly, I consider the SU 35 to be a monkey model aircraft in comparison to the PAK FA. Although the Russian Air Force is going to cut the number of PAK FAs it is going to acquire, it is only getting relatively small numbers of SU 35s....funny that.

Personally, I think that APG 63 (v3), legion IRSTand EPAWSS equipped F15Cs will give the SU 35s a very good run for its money. The SU 35 is just ain't all that!


Banned
 
Posts: 984
Joined: 24 Sep 2014, 22:56

by sergei » 13 Apr 2015, 20:42

ata wrote:
shrimpman wrote:You created a lot of questions in my head, Ata :) America is still asleep, I will keep close attention to what they are going to say. Sorry for my uneducated opinion, but there is something I cannot understand. Ever since I have found this website and started to get familiar with the forum contents, I got a very clear image, that the biggest word, bar none, in military aviation nowadays is AESA. You say PESA can be just as powerful, or even stronger. Your calculations make sense, but I’m no physicist, gotta wait for Americans to wake up and brew up a reply. What bothers me is that I find it very hard to believe PESA would really be that effective. As far as I can speculate, Su-27 family is most closely resembling American F-15 in performance, radar size and role. And yet PESA equipped F-15’s are a duck soup against stealthy F-22. The only instance F-22 AESA radar was even detected was by F-35 as someone mentioned already couple weeks ago. Immediate assumption is that targeting F-35 would be a very challenging task as well, while F-35 LPI radar would have little trouble seeing non-stealthy objects at long distances. If a couple of AMRAAMS hanging on the external hardpoints makes the F-35 quite easy to detect, then I would assume a Flanker armed with its 10 AA missiles would lit up like a Christmas tree even when hit with a relatively weak beam. Am I badly wrong here? I’m sorry to doubt your point, but it’s quite hard for me to grasp that idea. It feels a little bit like reading history books about pre-WWII generals arguing that all-metal monoplanes were a ridiculous idea and that bi-planes were the way to go. Or your own marshal Budionny, who claimed in 1937 (IIRC) that tanks will never replace cavalry.


Well, these are good questions, actually. And, if you ask my opinion, I would say AESA is much better than PESA. Again, more power doesn't mean PESA is better. When I answered about PESA I only mentioned the statement AESA is more powerful. There are many limitations PESA technology has. So, of course if you can choose, then AESA is a best choice. BUT. If you need simply max detection range, then PESA will be (in general (!)) better then AESA. Point here is that brightest torch is not always better option. It all depends of situation.
About that statement F-22 radar was only detected by F-35. What is source, first of all? I'd like also to know more about conditions. Of course LPI makes sense. In equal conditions if you transmit less power you're less visible. It's obvious. So, maybe F-15 simply has no that algorithm as I mentioned to process many small peaks. BTW I'm not sure if Flanker is able to do that, I only said it's possible in theory. Maybe something else was different from our "ideal situation", I don't know. I only want to say LPI as well as "stealth" is not something magical, and it required details to be applied to any tactical modelling.

PESA has a number of advantages over AESA which AESA will never reach:simplicity of design compared AESA-emerging from this better cooling -more power -more range- low cost.
P/S " radar size" Not for first Su-27 variant , it have some minor advance in radar range but all rest radar performance worse .


Banned
 
Posts: 984
Joined: 24 Sep 2014, 22:56

by sergei » 13 Apr 2015, 20:59

---------------
"what about cruising speed? not faster than F-35 i bet"
If my memory serves me something like 0.85m+ for F35 and 1.01 for Su-35[/quote]

I call BS on that, if i remember correctly 1.1 or 1.2 was achieved when the aircraft was clean, if you have 8 A2A missiles hanging off that thing its cruise will be .95 for any flight planning on lasting longer then 30 min. The F-35 cruise speed depends on mission profile it can do as low as .75 for CAS and strike for maximum fuel efficiency or up to 1.2-1.3 for 150nm for "efficient" dash speed.
----------------------------

"if you have 8 A2A missiles" Want to see F35 have them all inside.
"The F-35 cruise speed depends on mission" Su-35 too oddly enough, and 8 A2A sounds a lot lighter than 8 A2G for CAS
Not Su-35 Not F-35 not created originally for Super-cruise they will never reach the performance F-22,T-50, or Mig-31 and Sr-71.
Cruise speed 1.1m for Su-35 is a small bonus for very good thrust-to-weight ratio discovered during tests.


Banned
 
Posts: 984
Joined: 24 Sep 2014, 22:56

by sergei » 13 Apr 2015, 21:51

--------------------------------------------
in theory due to TVC su-35 will have better max turn rate, lower wing loading will likely give it better sustain turn performance at high altitude , by contrast F-35 high wing loading will give it better roll rate, dive rate, sustain turn ability at low altitude,
--------------------------------------
Su-27vs F16 combat load 4 A2A+50% fuel
Su27 have better max turn on altitude 200m-7000m and speed 300kmh-700kmh,better sustain turn on altitude 200m-7000m and speed 300kmh-1200kmh
F16 have equal max turn on altitude 200m-7000m and speed 700kmh-1200kmh
---------
Su-35 better Su-27
F35 need to be much better F16 to beat Su-35.


Elite 3K
Elite 3K
 
Posts: 3768
Joined: 03 Mar 2010, 03:12

by madrat » 13 Apr 2015, 22:51

You go ahead and use TVC to swing your nose on target. You're momentum is decreasing rapidly at that point. You just turned your energy advantage on its head.

If what ata is saying is right then LPI is going to track targets with minimal energy. Does that mean you cannot search for other targets in the direction of the tracks without revealing your position? And if your AESA relies on a single frequency at any one moment, does that mean your amplitude of the signal is dependent on the nearest track?


User avatar
Elite 2K
Elite 2K
 
Posts: 2328
Joined: 27 Mar 2015, 16:05

by eloise » 14 Apr 2015, 03:01

geforcerfx wrote:Well I found this

"The engine gives the Su-35 limited supercruise capability, or sustained supersonic speed without the use of afterburners.[47] Radar-absorbent material is applied to the engine inlets and the front stages of the engine compressor to halve the Su-35's frontal radar cross-section (RCS); the canopy was also modified to deflect radar waves.[48]"

on Wikipedia (whoop) with some articles linked, I thought I remembered seeing the Su-35 had S-Ducts but they have some kind of RAM applied to the engine, somehow. Prob still not half the Su-27 but I would venture a guess the Su-35 is definitely not the exact same signature as the Su-27, the real question is do they keep up on the ram maintenance on the Su-35.


geforcerfx : neither Su-27 or Su-35 have S ducts
also the RAM applied to the engine fan blade , pylon and airframe was what reduced Su-27 RCS to around 10 m2 as stated in the link , without the RAM applied to these area the RCS of Su-27 will be significantly higher
Image
http://vivovoco.astronet.ru/VV/JOURNAL/ ... STELLS.HTM


User avatar
Elite 2K
Elite 2K
 
Posts: 2328
Joined: 27 Mar 2015, 16:05

by eloise » 14 Apr 2015, 03:17

ata wrote:Image

What is the angle of the shot?

And here:
Image

And here:
Image

And here:
Image

So, the angle I would say about 30 degrees at max. If not 45.

I cannot see the engine fan blade in any of these picture :shock:

ata wrote:This is what I mean, add here "side view" and "from the top and bottom" -> RCS ALWAYS needs to be indicated at min at max value. At least at tactically meaningful directions. Front direction doesn't make us able to make any conclusion.

frontal direction is obviously the most important direction :? , for example if F-35 was to attack an Su-35 airfield , and the Su-35 take off to defense themselves , wouldnt they come at the other head on ?
ata wrote: F-117 is an ottoman with wings and powerful engine. It even has no radar at all (which we remember is very important from RCS point of view), and even that "all in the name of stealthy" was downed when it touched more or less effective SAM. So, it's not a good reference point.

F-117 was designed 40-50 years before the F-35 , and even with low band radar the Serbia was only able to shot it down 1 time out of over 1000 sorties , and only from 12 km :) , i have to say that is pretty impressive achievement
ata wrote: And "similar shape" is perfect. All the aircrafts have more or less similar shape. Body, tail, wings.... Sorry, I'm joking. In fact, as I said it's incredibly hard to know in advance which parts of the body will affect RCS and which will not. Even it's quite useless to model "metal body" because main impact caused by internal parts, of something sticks out from the body (like EOTS).

every part of aircraft body will affect RCS , unless your fighter is transparent to radar wave , the graph was to estimated because you want to know in what direction stealth fighter will have high RCS , and in what direction it will have small RCS , the way radar wave scatter


ata wrote:I'm not quite good at drawing. Well.... I'm really bad at that. Anyway: http://flockdraw.com/gallery/view/2020723
So, of course F-35 can turn... but we're talking about distances like 100-150 km, which means Flanker already knows that F-35 in that direction and even if it disappeared from radar it will take 10-20 seconds to reach the range where it will appear again. Of course F-35 can attack at that time, but it will be using radar in that case, and we already discussed it mean the same as F-35 is not stealthy at that time.

ok how the Su-35 suddently know what the direction of F-35 to turn its radar that way ? , what stop the F-35 from turnning its nose to Su-35 direction ? , even if Su-35 cruise at mach 2 , it still take 221 second to cover 150 km and obviously Su-35 cannot reach mach 2 with 10 AAM , and when f-35 turn it's nose to Su-35 direction , it will be disappear from the radar screen , thus Su-35 will be blindly rushing to F-35 direction , what stop the F-35 from attacking the blind Su-35 ? , remember the faster you go , the bigger your turn radius and the smaller G you can pull , making your aircraft an easy target to hit
ata wrote: but S-300/400 which doesn't care of stealth at all, it's able to detect them all as soon as they get up from horizon. And because in new versions it's able to down planes from 400 km.... well, it's not that obvious.
That's why we're talking about F-35 vs Su-35 face to face.

just because S-400/500 can take down aircraft from 400 km doesnt mean they be able to detect stealth fighter at that range , the detection and tracking range again stealth fighter will be significantly shorter , there is no way S-400/500 can detect stealth fighter as soon as they get up from horizon , if S-300/400 doesnt care about stealth at all , then no one would waste time with low frequency radar
btw according to gen Hostage F-35 was designed to neutralize S-400 and their cousin


PreviousNext

Who is online
Users browsing this forum: No registered users and 16 guests