Satorian30 percent to 60 percent?
What’s the remaining 10 percent, if neither single-seater nor twin-seater? :eek::p
SatorianOriginally Posted by METEORSWARM
Efa supercruiser is 1,5 mach with external tank(1000)+4 asraam + 2 iris t.
Got any sources for that? Seems to be beyond anything I’ve seen credibly sourced.
http://www.maclittle.es/02/04/2009/eurofighter-ef-2000delivering.html
2 tipes supercruiser inside f-22 and efa.
Supercruiser sustained(all time) or not sustained( long time use supercruiser top speed). – –
– –
f-22 1,5mach 1,8 mach
Efa 1,2mach” 1,5 mach”“4 amraam or (meteor) + 1 tank 1000”
Any sources? And what is non-sustained supercruise supposed to be?
Efa option upgrade ej200 in t3 + 30% more power inside engine. 1,5mach conversion to 1,8 mach no sustained and 1,2 mach to 1,5 mach sustained.
Efa option upgrade CFT.
Greetings
Got any sources for the speeds you come up with? I’d be delighted to know how a 30% power increase is supposed to yield a 25% velocity increase at these base speeds.
SatorianRR said 56k for the F136 in AvWeek. Does that make it true?
I’m not sure I see your point here. Are you trying to compare a claim on some (apparently) rough projection with the claim of a test pilot who has flown a development version recently?
Am I the one with a history of defending PR claims?
SatorianI want to know what happened to the 56,000lbs of thrust figure for the F136 Rolls Royce mentioned in AvWeek several years ago.
How should I know? Why should I know?
SatorianAs explained in a previous post in another thread most certainly just thinking of the 41,100 lbs hover thrust the F135-600 demonstrated.
That would be a rather mindless mistake, especially as all those TWR calculation should take up a fair amount of his attention.
I have hear Beesley use the 48,000 lbs as well…
Where? Got a link?
SatorianNo, Boeing knows full well that it is a physical & technological impossibility for the F-15SE to obtain the same level of stealth as the F-35.
Even when restricting this claim to frontal aspect RCS? And that still doesn’t explain where the word play was supposed to be.
SatorianNope, misreporting/misinterpreting what Boeing has actually said. I challenge you to find an actual quote (not what some reporter says it has said) from Boeing that even mentions the F-35.
“Jones says the F-15 Silent Eagle can be made as stealthy from the front aspect as an F-35 using RCS-reducing techniques incorporated into the design.”
http://www.aviationweek.com/aw/jsp_includes/articlePrint.jsp?storyID=news/aw032309p1.xml&headLine=Stealthy%20F-15%20Could%20Breathe%20Life%20into%20St.%20Louis%20Facility
‘Jones’ refers to Brad Jones, Boeing’s F-15 future programs director. Or do you want to claim that Amy Butler of Aviation Week is lying and putting words in his mouth?
SatorianNope, misreporting/misinterpreting what Boeing has actually said. I challenge you to find an actual quote (not what some reporter says it has said) from Boeing that even mentions the F-35.
That would require me to have access to Boeing and what they said and/or released to those outlets.
No, it was playing word games with the intent of expressing that the F-15SE’s frontal RCS could be as low as the DOD is likely to allow.
They said they’d hope to be allowed to export stealth at the same level as the F-35. Where’s the word play?
SatorianNo it does not. Journalist are misinterpreting what Boeing has said to mean that. Read Boeing’s actual statements for yourself – no mention of the F-35 whatsoever…
“Boeing says the coatings could contibute to an equivalent amount of front-aspect stealth as that offered by Lockheed’s F-35.”
http://www.aviationweek.com/aw/generic/story.jsp?id=news/Silent031709.xml&headline=Boeing%20Unveils%20New%20Stealthy%20F-15&channel=defense
“First, Boeing says the F-15SE can match the frontal-aspect stealth performance of the export version of the Lockheed Martin F-35 Joint Strike Fighter. The precise level stealth allowed to be exported to foreign countries is still to be determined by the US authorities who govern technology transfer rules.”
http://www.flightglobal.com/blogs/the-dewline/2009/03/boeing-unveils-the-stealthy-f-.html
Boeing has since clarified its statment to make it more clear what it means. Which is basically that the F-15SE’s frontal RCS is likley to be limited by what the US DOD will allow to be exported rather than what it believes it is capable of doing.
They stated their hope that the US administration will allow them export it in a stealth configuration on a level with the F-35 (even if only considering frontal aspect perhaps), calling it “a level playing field”. Which should mean they are confident of being able to achieve that level of stealth.
SatorianRadar Absorbing Materials and Radar Absorbing Structure on the airplane’s Outer Mold Line (OML) deflects a portion of incoming RF energy, while another portion of RF is converted into a tiny amount of heat and a lot of static electricity. The heat stays local to where the RF first impinged, but the electricity follows the airplane’s OML to locations where it is bled off. Now, tell me what happens when a static charge reaches an electrical discontinuity on the OML? (This is waveguide physics 101.)
I have no clue. While I already don’t know what an electrical discontinuity exactly is, given that English isn’t my native tongue and I couldn’t find an exact translation, I admittedly don’t know a lot about electromagnetic physics either.
While your reply might have been an indirect answer (that exceeded my comprehension) to my question, I think I’ll explain my question a bit: I wondered about stealth development rate/speed and to what extent current non-US projects could decrease the gap to the US, when lessons about stealth that took days now take minutes, and conversely insights that needed years could be gotten in days or weeks. Would respectably funded and staffed projects like the PAK-FA be able to get near F-22 levels? If not, how long would it still take them to get there?
Also, how “maxed out” is stealth development, especially in terms of materials and shaping, currently? Are significant leaps still foreseeable or is it pretty much done for the moment, with no improvements significant enough to warrant a new type coming?
SatorianDJ said that they decided not to do it. He did not say it was impossible.
SatorianYes, there is convergence of analytical and empirical data as the mesh cell size decreases.
Yes, I understood that, but convergence per se also happens when going from 40% accuracy to 45%. But is there a specific mesh resolution where we get to about 98% or 99% accuracy and hit diminishing returns hard when adding resolution beyond that? At which resolution does accuracy increase per mesh increase hit nearly zero?
The trick involves electrical discontinuities.
That went right over my head. 🙂 What do you mean by that?
SatorianWell, the F-35’s RCS is also just LM’s claim 🙂
Indeed, which makes a claim based upon a claim even less sound to base a decision on. 🙂
I’d love to know what the F-35 RCS actually is supposed to be from requirements (ignoring the marble / golf ball statements).
SatorianRCS computer prediction techniques require the outer mold line be broken into triangular cell mesh similar to the finite element analysis mesh used by structural engineers. The 1970s vintage IBM 360 used for Have Blue and F-117 RCS analysis was unable to handle anything other than a very coarse mesh and took the better part of 2 days of CPU time to complete.
Today, the mesh used for RCS prediction is fine enough that it matches actual RCS measurements very precisely. The supercomputer CPU time needed to predict the RCS of an F-35 sized airplane is measured in minutes, not days.
Is there a tessellation limit or ratio where RCS prediction levels off in terms of accuracy? n polygons per area or angle?
Given that the equations are known and processing power is fairly ubiquitous, and assuming that design iteration intervals came down to minutes rather than days, where does that leave countries and companies that are currently trying to catch up in the stealth game?
SatorianOh dear.
1. Twin engines – Operation at long ranges with fewer A2A refuelings.
How does having two engines translate into longer range or fewer refuelings?
2. Two-seater – Two sets of brains, eyes and ears are four times better than one, and it aids in splitting the workload.
Given modern MMI and sensors on par with the F-35, the second seat could just as well be ballast, taking away room for avionics and fuel.
3. Higher T2W ratio – It boils down to better synchronization of energy-maneuverability.
“Synchronization of energy-maneuverability.” ?
Higher TWR offers more energy and typically allows greater freedom in maneuverability, but where does the concept of synchronization come in?
4. RCS – It is approximately the same as that of an export model F-35.
Boeing claims that the frontal RCS is comparable to that of an export F-35. There are all kinds of pitfalls in that.
5. Maximum growth potential – The Silent Eagle has reached the zenith of the Eagle family of air superiority fighters and fighter bombers.
If something is at its zenith, that means it can’t rise any higher, because it is at its highest point of trajectory. That means there is exactly zero growth potential.
Being at a zenith and having maximum growth potential are mutually exclusive.
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