Cola1973To the best of my knowledge, no.
However, F-35’s 360° IIR fusion picture (if gets projected on pilot’s visor), may well change this. Ok, it may not draw exact aircraft in 3D, but it may give positions and possibly vectors (depends on DASS hardware) and that’s more than enough.
Cola1973At least, we do have some rough data from US sources about the F-22A.
200 nm supercruise and 620 nm subsonic for a real mission.
400 nm supercruise and 200 nm subsonic for a real mission.
With a fuel-load of 11900 kg (+2 ETs) 1600 nm subsonic.
To do supercruise, the fuel consumption does double in general.
Yes, I saw that one too.
By my calc, it turned out the F22 consumes about 20 kg/nm on Mach 1.5 and about 7 kg/nm on subsonic (guess Mach 0.8) cruise.
I may be wrong (the data is really rough), but it seems the SC consumption triples, actually…
Cola1973Sens is correct in the sense that the true thrust data is hard to ontain. However, for practical purposes, the data you presented is useful and can be used to gain results with limited fidelity. The quoted effects of inlet and outlet design really kick in beyond M1.8. Up to that point some heuristic corrections on inlet pressure loss can be used.
I would define supercruise as the ability to cruise behind the transonic drag peak, which translates into a Mach number of 1.1-1.3. In practical terms, what really matters is the specific range, the distance travelled for one unit of fuel.
For 4th generation aircraft that dropped between 60 and 80% between M0.8 and M1.4, while the F-22 experiences a drop of roughly 40-50%.
For advanced reading:
http://forum.keypublishing.co.uk/showpost.php?p=1344565&postcount=27
The relative change in specific range bears some dangers: by my defintion the B-58 was a supercruise aircraft, the SR-71 too. But both design have abismal specific range in subsonic regime. So, the ~50% rule should only be applied to aircraft of current technological standards with satisfying subsonic specific range.
The data for the F15 are the data for THE F15/F100, not bench F100. You can’t really calculate all the factors that influence the flight, so hence measurement. However, once you get the end result, you can more easy break it into consisting elements.
If one wants to compare it to F22/F119, he should get the same type of table. The F119 bench data are hardly representative.
My point from some posts ago is, it would be interesting to see what would the F15/F119 have to say about F22/F119’s performance.
Now, I simply tried to explain the principle of working, just so the members don’t argue over known facts, but can concentrate their arguments and researches on other areas, less known or covered before.
It’s strange though, that you quote the table from the very same document, you dismissed some time ago…
As for the SC definition, I’d agree with you, although the original definition (from 70s) is set as just flying supersonic without A/B.
Cola19731) Too bad the EF didn’t meet this requirement, while the F 22 surpass its own requirement :diablo:
2) So now the EF is more “aerodynamically super advanced” than the F 22 ?:p
3) He was polite: the guy was a guest in UK and was offered a ride in their newest fighter. What could he say?
1) I don’t see how EF didn’t meet the requirement?! EF actually FLIES Mach 1.5 with recessed AAMs, with EJ200… :confused:
It’s true that F22 surpasses it’s requirement, never argued that.
2) Well it was in 80s and the funny thing it still is still today. This has been explained a few times on this forum, so feel free to dig around.
3) EF is F1, while F22 is NASCAR, or IndyCar or whatever. Again, there isn’t much point arguing about that.
If you’re flaming then ok ;), but if you really believe what you post, don’t.
Cola1973“…to declare their total commitment to the ultra-advanced aircraft.” < LOL. I mean, just check the way the canopy opens. How does one eject if explosive bolts don’t (or just partially) detonate?!
BTW, does LM pay author’s fee to SAAB?? F35 code has already been taken by Danish Drakkens. 😉
Cola1973I just dug out, some data from way back. Curiously, Eurofighter (then called ACA/EAP/TKF/JF90) originally had the same operational requirement of SC Mach 1.5, just like the ATF did.
So, while the Europe prepared an aerodynamically super advanced and nimble interceptor, US went for a stealthy and more endurable version of the similar op req.
This is why Jumper said for EF and F22, they’re like “F1 and NASCAR”, although he forgot to say which is which. 😉
It’s not accident that EF supercruises, after all, since it was it’s original op. req, way back in early 80s.
Cola1973No, supercruise was coined/defined by the USAF/DOD in describing the capability criteria for the AFT (now F-22). For that the threashold for supercruise is Mach 1.5. But others wanted to play “me too” (prior to the AFT it was not even considered a big deal/significant) & started describing their aircraft’s ability to cruise supersonically as supercruising.
Yes well, check this entry under “Military use”.
http://en.wikipedia.org/wiki/Supercruise
(btw1, check who invented the term SC! Your very enemy Pierre Sprey, ROFLMAO ! ! !)
(btw2, it isn’t AFT, but ATF > Advanced Tactical Fighter! ! !)
Cola1973Mearly being supersonic does not mean you are supercruising…
No, ability to stay above Mach 1.5
No, Mach 1.2-1.3. Mach 1.5 is estimated with uprated (EJ220) engines.
AYAYAYAYAY, pfcem.
Cruising at SUBsonic speeds is “SUBcrusing” or just “cruising”. (Mach <~0.8)
Cruising at TRANSonic speeds is “TRANScruising”. (Mach ~0.8 – ~1.2)
Cruising at SUPERsonic speeds is “SUPERcruising”. (Mach >~1.2)
That has nothing to do with Mach 1.5 whatsoever/LOL, but with natural phenomenon called sound barrier. I may be wrong, but I don’t think LM patented air. 🙂
As for EF, official figures claim it can go Mach 1.5 with 4*recessed AIMs, but otherwise clean (no FTs or other weapons).
Cola1973Cola,
Boeing officials said, on the record, that the F-15’s RCS reduction was not of the same order of magnitude as an aircraft designed and built for LO. Everyone assumed they meant the F-35, but on being asked, they made it clear that they were referring to the Super Hornet. In other words, the F-15SE has a smaller RCS than a bog-standard Eagle, but a higher frontal RCS than an F/A-18E/F.
It’s a more survivable Eagle, in other words, not a ‘kick down the door, day one Stealth fighter’.
Oh, man! I though you’re gonna pull some bizarre and shocking revelation. 🙂
Anyway, thanks, Jackonicko.
It’s a bit odd though, how did the SH got into 5th generation, not that I mind generations, but this way it looks a little bit overstretched, if not pathetic, especially since Eurocanards supposedly aren’t enter 5th gen company?! LOL.
Cola1973I did wrote it several times before, but it maybe you are new here. Real engine values do come from the bench-stand only. The other are calculated or mathematical ones.
Hm, why would one calculate its thrust when can measure it? I mean this guys have those planes in garage. They aren’t poor *******s like us. 🙂
From the bench comes uninstalled thrust, but it comes without actual aircraft configuration around it, so isn’t exactly representative…
The gas-medium is air and taken from the atmosphere, which is no day to the “so called” standard atmosphere with the related variations in thrust, see the June 22 at your home-town at 12 a.m. about that and do compare that with the conditions at 7 a.m. f.e.
…Yes it’s a “standard atmosphere” and is commonly used for calculations…so?
When at s.l. your real thrust is 100%it is at ~36.000 feet ~30% only.
Now, that heavily depends on the engine type/characteristics. If F100 is at 30%/30,000ft, that doesn’t mean the F119 is at 30%/30,000ft as well. Fans and jets are different indeed, especially at high speeds, meaning high altitude as well.
A figure “inlet-loss = 12%” for example, may well be true for F16, but hardly for F15, or vice versa.
I’m not exactly sure what are you getting at here?
Cola1973Clutter isn’t going to be an issue if the Raptor’s target is flying at an altitude of 8000m. If the target isn’t a VLO target then the Raptor’s radar will have a longer detection range than any fighter sized IRST I’m aware of. Additionally, to get max range out of the IRST, the field of view is going to be very small, making detection that much more difficult. If the Raptor is aware of the target, then breaking an IR track will be even easier, as it won’t be difficult to get out of a narrow field of view sensor, with some aggressive manuevering.
Well, I could just prove you wrong, but that’s beside the point. The trouble is you fail to recognize the principle and that’s not smart. 😉
Cola1973After, say M1.5, the compression is not done by the compression blades any more, it’s done by the compression from the air hitting the inlet, as a matter of fact using the compressor the inlet has to slow down the air to subsonic before accelerating to to supersonic again, this is the geniality of ramjet, complete simplicity.
Mig25’s engines, f.e., retract the whole engine core at Mach ~2.8 (not M 0.8) and then Mig flies like a pure ramjet, but it still requires turbines up until M 2.8, if I understood Sens’ comment correctly.
When you talk of ram effects and engine duct, keep in mind that you can’t feed the engine with supersonic airflow, because the engine will get busted. So, EVERY engine duct MUST slow air to subsonic speed (and that begins at around M0.8, indeed), before entering turbine and that’s what engine duct is used for in the first place. Why build a drag feature, if you don’t need it? A10, or A330 don’t have ram ducts, because being subsonic they don’t need it. Many planes are speed limited by the geometry of their ducts, rather than overall aerodynamics.
F15’s F100 from the table, has positive airflow (positive net thrust) up until M1.2, in military thrust. This is because, at M1.2 the turbine has reached the peak of its core airflow allowance (RPM, pressure, temperature, etc…) and can’t give more airflow through the core. Now, this is a spot where the afterburner kicks in and propels aircraft even faster, while the core flow actually drags the plane. So, theoretically, a common F15 can SC if drag permits (clean condition and such), but has engine (F100) limit of Mach ~1.2.
To conclude, the engine duct doesn’t compress air because it’s a compressor as such, but the compression is a byproduct of the need to reduce airflow speed to subsonic. At higher speeds ram (engine) ducts add so much drag (the air begins to “spill out” of airflow, causing interference) that the net thrust can’t exceed it and the aircraft flies its top speed.
Like in every other aspect of aircraft design, there’s no fixed formula for best performance, only operational requirements.
This is why the F119 is light years away from F135, in spite of claims the F135 being newer and more modern. F135 is a loaded with thrust indeed, but if you put it into F22, you can forget to match F119 engined F22 performance.
Cola1973Time-out guys 🙂
Both, EF and Rafale are excellent aircraft, most modern in their class and anyone who knows something about the aviation, realizes that.
What, I’d like to hear, Jackonicko, is the story you hinted about F15SE, something you picked up on this year’s LeBourget. Care to get more specific? 🙂
Thx.
Cola1973Be careful, because that data is about “mathematical” thrust. With rising speed and above Mach 0,8 most of that nominal thrust is generated by the inlet- and outlet-systemand not by the installed engine. Intresting is the net-thrust from that, when the air-pressure or drag do drop with the height. Besides oxygen-content cooling will become a limiting issue. To stay above 50000 feet most fighters have to be supersonic at all.
At sea level the practical limit is ~Mach 1,2 or 800 kt. The values above are mathematical ones and do show that practical limit too, when Mach 0,2 is the take-off speed already.
On that “mathematical” data, I assume you mean the data from the tables i gave. Now, if that’s the case, you’re wrong. The data from the table is a measured one, meaning in actual flying conditions with all variables applied, so it’s actually F-15’s thrust, not F100’s.
This is why you get no net thrust above Mach 1.2 (visible in Tmil and Tidle comparsion). The turbine flow hit it’s physical limit and is unable to move faster, but then afterburner takes over and ignites (accelerates) the bypass flow.
You can’t compare these charts to F119’s because F119 has a 0.2 bypass and this F100 has some ~0.7. The turbine mixture is more fuel saturated and grows more linear with speed, as opposed to F100’s.
“With rising speed and above Mach 0,8 most of that nominal thrust is generated by the inlet- and outlet-systemand not by the installed engine.”
Can’t say that I understood what you mean, so can you clarify that?
Cola1973The difference between “cruise” and “supercruise” (TM) :), in theory, is 1 knot!
One moment you’re subsonic and the other you’re supersonic and that makes SC merely a semantic category.
In reality it isn’t so.
The term supercruise is used to describe the aircraft’s ability to stay above its transonic velocity region (supersonic) without afterburner.
This is important because the aircraft has increased drag (and other unwanted effects) in its transonic speed region and cruising at transonic speeds is never economic, due that drag.
>>However, one should note that there are different transonic regions for different aircraft.<<
This means, that the scale of transonic region vary according to aircraft’s aerodynamics. So, some aircraft experience transonic effects in a very narrow part of the envelope (f.e. Mach 0.95-1.05), while others, experience it the larger one (f.e. Mach 0.9-1.1, or much larger).
So, there really isn’t a uniform number that encompasses all airframes.
The importance of supersonic flight in weapon’s range terms, translates into giving the weapon maximum kinetic energy.
In mathematical terms, this means that the missile adds it’s own max speed to the speed of the launching aircraft.
F.e., if the missile’s top speed is Mach 3 and the launching aircraft’s is 0.9, the missile will fly Mach 3.9 at motor burnout and thus have greater range than if launched from static (SAM) installation.
The only practical limit to this velocity synergy is the missile’s drag/structural limit.
Supersonic flight doesn’t require of a missile to go overcome its transonic region by its own thrust, but by using launcher’s (aircraft’s) one and that conserves fuel and increases the range and overall energy level, which means better chance to score a hit.
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