F-22 Speed = Mach 2.84 Calculations!!, page 5
Pages: <<  2    3    4    5  >>
ATS Members have flagged this thread 0 times


reply posted on 17-9-2008 @ 06:05 PM by WestPoint23
reply to post by intelgurl



From first hand pilot quotes I've come to believe that the F-22s top speed limit is the speed at which the airframe starts to fail and the aircraft can no longer maintain structural integrity. The engines have enough thrust, and the jet is aerodynamic enough to basically destroy itself if not careful. As far as its top safe speed, I too think it's below Mach 2.5, but not by much. The now infamous Dozer (damn ridiculous AFOSI) stated that its top super-cruise speed is not that far behind its top overall speed and that the F-22 was very much a Mach 2 capable fighter. A statement which should rightly lead one to ask, Mach 2 super-cruise given certain paramatars?

[edit on 17-9-2008 by WestPoint23]


reply posted on 18-9-2008 @ 09:10 AM by emile
ACCORDING TO WIKI RENEWED IT IS 2.25 MACH, NOT SO FAST AS SOMEBODY IMAGED.



reply posted on 23-10-2008 @ 05:26 AM by Anonymous ATS
First off, you have the Raptors numbers all wrong! max takeoff is 72,000lbs (It will never be at that weight while fighting) The weight that the Raptor will be fighting at is 58,200lbs! A 30,300lb air frame, 2,680lbs of air to air weapons, 6 Aim120's, 2 Aim9's, 480rnds of 20mm to go along with it's massive 25,000lbs of internal fuel and the pilot with gear 220lbs.

The official thrust of the F119 is 37,800lbs X 2 =75,600lbs.

Thrust to weight ratio in an air to air configuration is right at 1.30:1 on the runway and over 1.50:1 at the fight scenario, this tops all fighters! Compare this to the F-15s air to air of 1.10:1 Typhoons at 1.08:1, Mig-35 0.98:1 Rafales 0.91:1, SU-27's 0.89:1 and the SU-30's 0.81:1.

I work for Pratt & Whitney and have for 14 years, my Dad worked for PW and was one of the engineers on the original F100 team. I was on the F119-PW-100 team for 10 years. I'm now working on the F119-PW-200.

I'll let you all figure out the speed of the Raptor, but remember this, the Raptor will always have the weapons and fuel internally when it counts! which means far less resistance compared to any other fighter, even when they don't hang weapons! Compare the lines of a Typhoon then the Raptors! The Raptors body panels are near invisable, they seem to melt into each other and the lines can't be matched by any aircraft. You wont find any angles pointing in the wrong direction to upset it's aerodynamics!

The F119's have an upper intake that bypasses the engine entirely during extreme high speeds , these stay closed when maximum stealth is needed. The structure and materials used on the F-22's air frame and skin are able to handle very high speeds also. Think of it this way>

More slippery than an F-15......


reply posted on 5-3-2009 @ 06:56 PM by Fearofthedark
Originally posted by Anonymous ATS
First off, you have the Raptors numbers all wrong! max takeoff is 72,000lbs (It will never be at that weight while fighting) The weight that the Raptor will be fighting at is 58,200lbs! A 30,300lb air frame, 2,680lbs of air to air weapons, 6 Aim120's, 2 Aim9's, 480rnds of 20mm to go along with it's massive 25,000lbs of internal fuel and the pilot with gear 220lbs.

The official thrust of the F119 is 37,800lbs X 2 =75,600lbs.

Thrust to weight ratio in an air to air configuration is right at 1.30:1 on the runway and over 1.50:1 at the fight scenario, this tops all fighters! Compare this to the F-15s air to air of 1.10:1 Typhoons at 1.08:1, Mig-35 0.98:1 Rafales 0.91:1, SU-27's 0.89:1 and the SU-30's 0.81:1.

I work for Pratt & Whitney and have for 14 years, my Dad worked for PW and was one of the engineers on the original F100 team. I was on the F119-PW-100 team for 10 years. I'm now working on the F119-PW-200.

I'll let you all figure out the speed of the Raptor, but remember this, the Raptor will always have the weapons and fuel internally when it counts! which means far less resistance compared to any other fighter, even when they don't hang weapons! Compare the lines of a Typhoon then the Raptors! The Raptors body panels are near invisable, they seem to melt into each other and the lines can't be matched by any aircraft. You wont find any angles pointing in the wrong direction to upset it's aerodynamics!

The F119's have an upper intake that bypasses the engine entirely during extreme high speeds , these stay closed when maximum stealth is needed. The structure and materials used on the F-22's air frame and skin are able to handle very high speeds also. Think of it this way>

More slippery than an F-15......


Could the F119 be mounted on the F-15? I believe they have about the same diameter ( without the exhaust) but I'm not sure.

How much more power does the F119 produced in military thrust compared to the F100-PW-232 at say Mach 1.5?

Thx.


reply posted on 22-3-2009 @ 02:44 PM by big_m
Originally posted by TACHYON
Originally posted by NickS1004
If the F-22 does indeed have variable intakes, i would say its mach 3 capable, if it doesnt.. mach 2 is more likely

>>I know a way to find out.
From:
www.grc.nasa.gov/WWWK-12/WindTunnel/Activities/lift_formula.html ,
the folowing was abstracted:

L = (1/2) d V^2 S Cl
where,
L = lift in lbs.
d = air density at a particular altitude
V^2 = velocity squared in ft/sec (not ft/sec/sec, that's acceleration)
Cl = coefficient of lift, a decimal figure, usually less than 1.

Also they listed d = .00046 @ 4,000'
= .000362 @ 50,000'
= .000285 @ 55,000'
by division of higher altitudes into lower ones, I extrapolate, multiplying by .78 for each 5,000 ft. increase:
.0001055 @ 70,000'
.00008223 @ 75,000'
.0000642 @ 80,000'

Now assume the wing area and flying weight (given on the site above) is 830 sq. ft. and 56,000 lbs.; and the Cl is .5 @ 4 deg. angle-of-attack (also graph extrapolated on the site), and 1,900 ft/sec as forward air speed, then,

L = (1/2) * .00008223 * 3,610,000 * 830 * .5 = 61,596.4 lbs.
(The F-22 has the wing lift to fly level at Mach 2.9 -3.0 at 80,000 ft. according to a subsonic-applicable algebraic formula)

This was calculated on my TI-30.
Whether or not the engines or intakes will function at that speed or altitude is still questionable. I know the subsonic *maximum speed* formula only by memory, but I can't provide a reference other than a 50 yr. old college textbook that's in storage now.
Pages: <<  2    3    4    5  >>    ^^TOP^^



In Case Of Videos Of Flying People
  Posted 11 days ago with 9 member flags
First flight for \'flapless\' plane - the Evolution of Aviation
  Posted 14 days ago with 4 member flags
F22 mishap or more that meeets the eye?
  Posted 3 days ago with 4 member flags
Boeing X-37 and X-40 - the ultimate history
  Posted 7 days ago with 3 member flags
Its a bird, its a plane, no its a ....
  Posted 16 days ago with 0 member flags