### Re: Operational Performace Comparison: Viper, Beagle, and St

Posted:

**06 May 2019, 22:30**Or catch it when it is still subsonic like the Iranian F-5 did with the Iraqi MiG-25.

Military Aviation Forum

http://www.f-16.net/forum/

Page **76** of **120**

Posted: **06 May 2019, 22:30**

Or catch it when it is still subsonic like the Iranian F-5 did with the Iraqi MiG-25.

Posted: **07 May 2019, 02:03**

eloise wrote:Meteor's booster is 69% the length of AIM-120B's propellant

Meteor's ramjet propellant stage (not including control valve,fuel injector, MSIU, IB-igniter) is 40% the length of AIM-120B's propellant

Because the IPS of ramjet engine is 3 times better than traditional rocket motors

=> Meteor ramjet propellant stage worth 40*3 = 120% the length of AIM-120B propellant

In total, 120+69 = 189%.

Is it correct to think Meteor is similar to AIM-120B with 189% fuel?

I went with total Meteor fuel equal to 109% at 3xISP. Total max burn time down to 30 seconds. 3 deg loft

110nm launch, a mere 2.27M max speed (min thrust). final speed 1.01M. Max alt 49,000ft. Flight range 73.5nm. this is the 36k M1 shooter and target head on. So this is still a tad better than the AIM-120D but it's not insane.

Posted: **07 May 2019, 02:35**

sprstdlyscottsmn wrote:I went with total Meteor fuel equal to 109% at 3xISP. Total max burn time down to 30 seconds. 3 deg loft

110nm launch, a mere 2.27M max speed (min thrust). final speed 1.01M. Max alt 49,000ft. Flight range 73.5nm. this is the 36k M1 shooter and target head on. So this is still a tad better than the AIM-120D but it's not insane.

can you do it with various loft profile similar to what you did with AIM-120D?

0 deg loft

a 41nm shot gives a final speed of 1.01M, peak speed of 4.85M, and a final distance of 28.4nm.

5 deg loft

a 44nm shot gives a final speed of 1.02M, peak speed of 4.87M, and a final distance of 31.5nm.

10 deg loft

a 53nm shot gives a final speed of 1.03M, peak speed of 4.85M, and a final distance of 38.2nm.

15 deg loft

a 71nm shot gives a final speed of 1.00M, peak speed of 4.84M, and a final distance of 51.0nm.

20 deg loft

a 95nm shot gives a final speed of 1.01M, peak speed of 4.81M, and a final distance of 68.7nm.

Is it possible for you to draw overlap chart between AIM-120D, Meteor and possibly AIM-54 like this: ?

https://jaesan-aero.blogspot.com/2019/0 ... art-3.html

Posted: **07 May 2019, 05:54**

Meteor case is designed to sustain high temperatures for several minutes

https://imemg.org/wp-content/uploads/20 ... 190517.pdf

Meteor when launched from 42,000 ft can maintain speed excess Mach 3 for several minutes

https://aviationweek.typepad.com/ares/2 ... eston.html

https://imemg.org/wp-content/uploads/20 ... 190517.pdf

Meteor when launched from 42,000 ft can maintain speed excess Mach 3 for several minutes

https://aviationweek.typepad.com/ares/2 ... eston.html

Posted: **07 May 2019, 06:28**

In my current version min thrust can last nearly three minutes from 36,000ft.

Posted: **07 May 2019, 07:21**

sprstdlyscottsmn wrote:I went with total Meteor fuel equal to 109% at 3xISP. Total max burn time down to 30 seconds. 3 deg loft

I realized something just now, only the ramjet fuel has 3x ISP

Meteor ramjet propellant stage is only 40% length of AIM-120's propellant

The booster of Meteor should have the same ISP as AIM-120's propellant

Posted: **07 May 2019, 12:54**

sprstdlyscottsmn wrote:I went with total Meteor fuel equal to 109% at 3xISP. Total max burn time down to 30 seconds. 3 deg loft

110nm launch, a mere 2.27M max speed (min thrust). final speed 1.01M. Max alt 49,000ft. Flight range 73.5nm. this is the 36k M1 shooter and target head on. So this is still a tad better than the AIM-120D but it's not insane.

Had they produced NCADE in large number, do you think its kinematic will be better than Meteor?

Posted: **07 May 2019, 13:51**

eloise wrote:I realized something just now, only the ramjet fuel has 3x ISP

Meteor ramjet propellant stage is only 40% length of AIM-120's propellant

The booster of Meteor should have the same ISP as AIM-120's propellant

What I did was size the booster to get it to M2 in 2 seconds from a subsonic launch. Right now the cruise phase is still M2 instead of accelerating to M3. Let me tweak that and see what comes up.

Posted: **07 May 2019, 15:21**

sprstdlyscottsmn wrote:What I did was size the booster to get it to M2 in 2 seconds from a subsonic launch. Right now the cruise phase is still M2 instead of accelerating to M3. Let me tweak that and see what comes up.

I guess that will reduce the range further.

Can you try with 10 or 15 degrees loft instead?

By the way do you have DCS, i heard it is very accurate

Posted: **07 May 2019, 15:32**

I do have DCS, and some of the modules are very accurate.

The issue I have with high loft is that the Meteor is airbreathing, so it can't do a 120,000ft loft like the AMRAAM or Phoenix.

The issue I have with high loft is that the Meteor is airbreathing, so it can't do a 120,000ft loft like the AMRAAM or Phoenix.

Posted: **07 May 2019, 15:53**

sprstdlyscottsmn wrote:I do have DCS, and some of the modules are very accurate.

The issue I have with high loft is that the Meteor is airbreathing, so it can't do a 120,000ft loft like the AMRAAM or Phoenix.

At what loft angle will it climb to 120,000 ft?

Can the missile flame out then restart on the way down? ( since it is already fast at the point?)

Posted: **07 May 2019, 16:06**

eloise wrote:At what loft angle will it climb to 120,000 ft?

Can the missile flame out then restart on the way down? ( since it is already fast at the point?)

depends 100% on the launch conditions. And I am going to say "no" on a relight. I don't expect the Meteor is meant to fly above, say, 85,000ft. That Grippen launch discussion mentions a 45,000ft launch, boost to M2, then cruise accel to Mach3 and at least 2min of operation. It never mentions climb to an altitude. This further reinforces to me that Meteor does not loft for range.

*edit* I say no to the relight because that is not how solid fuel motors work.

Posted: **07 May 2019, 20:40**

eloise wrote:For the sake of discussion

Photo of AIM-120B and Meteor's booster and fuel

Meteor's booster is 69% the length of AIM-120B's propellant

Meteor's ramjet propellant stage (not including control valve,fuel injector, MSIU, IB-igniter) is 40% the length of AIM-120B's propellant

Because the IPS of ramjet engine is 3 times better than traditional rocket motors

=> Meteor ramjet propellant stage worth 40*3 = 120% the length of AIM-120B propellant

In total, 120+69 = 189%.

Is it correct to think Meteor is similar to AIM-120B with 189% fuel?

When trying to make that comparison, there are lot of known unknowns, and a bunch of unknown unknowns as well

Instead of comparing actual missiles, I'll try to ballpark what ISP advantage a VFDR powered missile might have over a conventional solid rocket motor.

I imagine that ~20% of the propellant mass can be shaved off to account for the inlets and gas generator hardware that isn't needed on the conventional missile. Of the remaining ~80% fuel mass, maybe half of it is used for the booster to get the missile up to speed. The remaining ~40% is not devoid of oxidizer (the graphic describes it as "oxygen deficient"), so let's call it 2.5x ISP compared to a conventional solid rocket. That means we get 40% + (40% x 2.5) = 140% ISP, or a mere 40% advantage. Is that enough to overcome the increased drag of the inlets? Maybe in some (possibly most?) flight profiles, but probably not in all of them.

Obviously, I'm pulling the 20% and 2.5x numbers out of my posterior, but whatever those values are, they have to be accounted for. The ISP multiplier in particular will vary greatly with speed. I would expect something like 2.5x for the optimal speed (Mach 3 maybe?), but less as the speed goes up or down from there.

My gut tells me that Meteor will have a massive advantage over an AIM-120D when chasing down a bandit running away at low altitude, but the Slammer launched from altitude on a lofted trajectory will come very close to the performance of the Meteor, and may even beat it.

Posted: **07 May 2019, 21:00**

Spurts, did you see the Meteor launch at altitude I posted earlier ? Looking at the launch direction vs the Earth circumference it does visually appear to go on a gentle climb, looks about 20 degrees to me.

https://youtu.be/8dAmfVlcbp4?t=1m24s

viewtopic.php?p=414951#p414951

https://youtu.be/8dAmfVlcbp4?t=1m24s

viewtopic.php?p=414951#p414951

Posted: **07 May 2019, 21:41**

looks like a lens trick and a flat launch.