As I have said like a 100 times already, the ROTEX-T study uses the M112 as second stage, for a very high altitude burn.
So the burn time is expected to be longer.
Yeah, NASA is lying or stupid.
They should hire you for their thrust calculations!
A study that is not even presenting any acceleration charts, nor even any actual flight trajectory charts (which is the simplest of things to present) and instead presents a “predicted” flight trajectory chart.
And doesn’t even claim that the 26s is the actual burn time, but rather uses the term “nominal burn time” which essentially means that this is what is usually stated for this motor, cannot be used to invalidate NASA’s actual test data.
Yeah, people from the University of Oregon, Carthage college and NASA didn’t know how to calculate the thrust, but you do :)
There’s absolutely no need for a thrust curve.
The game doesn’t even model a thrust curve. It only models burn time and average thrust.
And there is no public thrust curve for most rockets in the game anyways.
What’s valid?
It’s literally using the thrust values given by the 2005 edition of the NASA handbook. (reference [33] in the article)
So the 2023 edition of the handbook is invalid because some study has used the thrust values of the 2005 edition to calculate the specific impulse?! :)
The source itself says “specific impulse of 2305 m/s … is assumed”! That’s the key word … “assumed”!
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You’re so blindly batting for a buff and ignoring evidence to the contrary. Don’t be surprised if it doesn’t get the results you want. You can’t ignore the fact that 295s impulse is literally impossible.
Yeah, “evidence to the contrary” :)
An article which is essentially saying: “Based on the thrust figures given in the 2005 edition of the handbook we assume that the specific impulse is …”
This is evidence that the revised thrust figures in the 2023 edition are wrong! :)
Well, according to you NASA is 100% infallible and couldn’t possibly accidentally claim a 1960s ammonium perchlorate propellant could achieve 295s impulse ASL…
You are yet to properly address how the I-HAWK motor could have such an implausibly high ISP.
And no “the AIM-7F is implemented incorrectly so the HAWK should be too” is not a valid answer.
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I’m not saying AIM-7F is implemented incorrectly.
I’m saying if AIM-7F has higher “apparent” thrust due to the drag reduction that the long burn of the motor causes, there is no reason why the same shouldn’t be reflected for the M112 as well.
That could be one of the possible explanations of why the thrust figures given for the M112 are relatively high.
And who says it’s implausible?
What’s your source?
There are two sources that confirm such high Isp (NASA’s handbook and the study in the section C of the main report)
And manufacturer’s patent also claims such high Isp.
So what’s you source on it being “implausible”? Your gut feeling?
Even the AIM-7F (1976), AIM-120 (1991), and other newer missiles do not exceed ~260s in surface conditions. It’s not remotely feasible - patents exaggerated claim or not.
It is VERY well known that the efficiency of solid rocket propellants did not exceed 270s ASL until the 2000s in actual applications.
Those motors use not only different propellants but different types of propellants.
Your argument is like saying: “There’s no way F-15, a plane from the 70s could be faster than F-35, a plane from 2010s”
That’s the worst comparison I’ve read all year. It shouldn’t need explanation that the F-35’s engine is far more efficient than the F-15’s… The other characteristics shaped by other factors do not directly correlate to missile booster propellant.
Newer propellants with higher energy density and efficiency should not be LESS efficient than already produced motors or they’d simply have reused that motor. If the specific impulse was that high, the AIM-54 would have been adapted to use it ASAP.
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If I recall the F-35 can’t maintain mach for long durations making it effectively subsonic unlike the F-15 or F/A-18.
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adding to your point
both the F-35 and the F-15 use the same fuel so the difference is made up by the F-15 being lighter and having more overall thrust despite having less powerful engines. the F-15 also has a much better airframe for going fast since it was designed from the ground up to be a fighter instead of a multirole aircraft
the main point being that there are other outside factors outside of how powerful the engine is that can majorly effect top speed
Y’all might be missing the point. The rocket motors are not comparable to the F-15 and development of the F-35 because rocket motors criteria for performance has never changed. Higher energy density is always sought provided shelf life and other factors meet criteria. It may have been possible for AP/Poly to do 300s impulse but it was never done in any real product because real life doesn’t work the exact same as “on paper”. The shelf life of those motors would probably have been terrible, or cost exorbitant.
In any case, the propellants of the time did not exceed 260s in the most optimal sea level conditions iirc.
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Not F-14 cockpit, but rather upgraded F-5 (Kowsar)'s cockpit.
And as I said before, there are no public information on whether there was any upgrades to the F-14(AM)'s cockpit, but just just as side information on what would be possible for F-14AM (which might or might not have happened already and might or might not happen in the future):
Seems like the right side MFD of the rear cockpit in the 6th picture, and possibly the right side MFD of the front cockpit in the 4th picture, is showing something like an RWR display. Or it could be for navigation. Perhaps both.
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Am I missing something here?
https://server.3rd-wing.net/public/Bureau_4thMEG/Procedures_communes/476TTP3-1.Threat_Guide-Public_Release.pdf Page 55
“The MIM-23B will accelerate to max speed (1200 KTAS) in approx. 5 seconds from launch with motor burnout occurring after 26
seconds. An unpowered non-manoeuvring MIM-23B will lose approx. 200 KTAS every 5 seconds.”
So according to this source, the acceleration is just shy of 12.6G or specificaly 123.466667 m/s^2.
The missile weighs 635 kg (584 kg was the 23A) so with these numbers, the booster thrust comes to 78401.3N.
Since it is the same motor and the Fakour weighs according to your sources 637.3 kg, and using the same formula, the thrust comes to 78685N…
So where does the 83900N come from?
Likewise, the 23B has a top speed of M2.5 or 1653,68 knots. Since it accelerates to 1200knots with the 5 second booster, the sustainer can only add around 450 knots. So with my calculations the 23B sustainer offers an acceleration of ~1.13G or specificaly 11.113886 m/s^2. I suppose that the booster fuel weight is 182kg (according to spreadsheet) for both the Fakour and the 23. So when the sustainer starts, the Hawk should weight 453kg and the Fakour 455,2973kg.
With these numbers the thrust for the Hawk 21 seconds sustainer comes to 5034,59N and to 5060,12N for the Fakour…
Now these calculations are pretty simple and dont factor a number of things like drag, gravity ect.
Despite that, the numbers, especialy for the sustainer vary by alot… What am I calculating wrong?
That acceleration is also attempting to overcome drag thus your values are lower than expected, same mistake I made in my initial point. It must also be said that the ramp-up and ramp-down in thrust means that some of that 5 seconds is actually not spent at peak acceleration.
Ah, whats the drag coefficient of the Fakour and do we know the drag coeffient of the Hawk as well ?
That’s not a source
That’s a DCS guide …
The spreadsheet number is made up by Gaijin, it has no source.
Obvious from the fact that they had gotten even the total propellant mass wrong and only corrected it after we bug reported it.
Not sure if no Fakour for the wing pylons is intended or WIP.
Because if anything, there’s no proof that the underbelly pylons can carry the Fakour (though one would assume given that it’s basically the same size and shape as AIM-54, and the ability to carry it on the underbelly pylons would basically be the main point of using the AIM-54 body instead of the MIM-23B Hawk body).
All the Fakour-90 (and AD-40A export variant/offering) test launch videos that exist have them mounted on the wing pylons.
Made a report here:
https://community.gaijin.net/issues/p/warthunder/i/tJKBcYkDfnCU
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Sorry my bad. Its posted here as as source and I didnt double check to see if its legit or not…