Comparison by Spurts

Unread postPosted: 19 Feb 2020, 15:07
by sprstdlyscottsmn
Hey all, my OG thread on this ended up locked. I wanted to say that I made a few updates to the missiles and I did something I normally don't do... I lifted the CFT AA stores carriage limit on the F-15SA. While I have no evidence of this actually happening the F-15SA/QA/EX seem to put an emphasis on AA work more than the Mudhen did, and as such I am making the assumption that the stores envelope was expanded. I realized I had done something similar with the Su-35S in removing it's max G shift through the trans-sonic and into the super sonic. No evidence, I am just assuming new improved versions also improve known weaknesses where reasonable.

Re: Comparison by Spurts

Unread postPosted: 20 Feb 2020, 18:52
by sprstdlyscottsmn
Here is the comparison currently. I am working on the F-16 model now.

Strike Fighters 2025_4.pdf
(1.74 MiB) Downloaded 700 times

Re: Comparison by Spurts

Unread postPosted: 20 Feb 2020, 19:40
by garrya
sprstdlyscottsmn wrote:Hey all, my OG thread on this ended up locked. I wanted to say that I made a few updates to the missiles and I did something I normally don't do... I lifted the CFT AA stores carriage limit on the F-15SA. While I have no evidence of this actually happening the F-15SA/QA/EX seem to put an emphasis on AA work more than the Mudhen did, and as such I am making the assumption that the stores envelope was expanded. I realized I had done something similar with the Su-35S in removing it's max G shift through the trans-sonic and into the super sonic. No evidence, I am just assuming new improved versions also improve known weaknesses where reasonable.

Why did it get locked, it is the best thread :(

Re: Comparison by Spurts

Unread postPosted: 20 Feb 2020, 19:43
by garrya
sprstdlyscottsmn wrote:Here is the comparison currently. I am working on the F-16 model now.

Strike Fighters 2025_4.pdf

Iam very grateful that you took the time in your day to bring us this master piece free of charge

Re: Comparison by Spurts

Unread postPosted: 21 Feb 2020, 08:10
by eloise
sprstdlyscottsmn wrote:Here is the comparison currently. I am working on the F-16 model now.

The attachment Strike Fighters 2025_4.pdf is no longer available

You are the best.
In the spot area section, do you consider the top view of the aircraft? I think the frontal view is better for comparison because aircraft are rarely viewed from the top
spot.PNG

and what is DPS? is it degree per second? why some missile turn better at longer distance?
dps.PNG

and I don't think SLAM-ER should have smaller RCS than SPEAR, they have similar shape and the later is a fraction the size of the former. SPEAR is in fact smaller than Meteor
Capture.PNG

231495_800.jpg

s_IMG4094-MBDA-Meteor-and-Spear-missiles.jpg

Re: Comparison by Spurts

Unread postPosted: 21 Feb 2020, 13:57
by sprstdlyscottsmn
eloise wrote:In the spot area section, do you consider the top view of the aircraft? I think the frontal view is better for comparison because aircraft are rarely viewed from the top

when looking at the size of an aircraft the critical issues are length and width. "height" is predominantly a factor of thin little vertical tails and landing gear length.

eloise wrote:and what is DPS? is it degree per second? why some missile turn better at longer distance?

Yes degrees per second. Some missiles appear to turn better at the end of their flight because they are now in denser air and/or are flying slower. A missile flying at twice it's corner velocity is not going to be able to turn as quickly at the same G.

eloise wrote:and I don't think SLAM-ER should have smaller RCS than SPEAR, they have similar shape and the later is a fraction the size of the former. SPEAR is in fact smaller than Meteor

Round nose with exposed seeker vs faceted nose. It boiled down to that.

Re: Comparison by Spurts

Unread postPosted: 21 Feb 2020, 18:43
by eloise
sprstdlyscottsmn wrote:when looking at the size of an aircraft the critical issues are length and width. "height" is predominantly a factor of thin little vertical tails and landing gear length.

I think length and width can be deceiving because they could have different wing shape and vastly different area
781CCA68-F06C-4390-80BB-6C93A1C59BC1.jpeg

sprstdlyscottsmn wrote:Round nose with exposed seeker vs faceted nose. It boiled down to that.

But SPEAR is very small, smaller than a short range air to air missile. And a short range air to air missile only has RCS about 0.03 m2 frontally
3F38801C-16E7-4575-A720-200A08B22357.jpeg

564688D1-CBD5-4237-8E94-65269AF62BB9.png

And SPEAR uses 3 tail fins instead of 4 tail fins like SLAM-ER. 4 fins design make right angle corners
0136BF52-A1CC-44C3-8215-5B10E5A904C2.jpeg

Re: Comparison by Spurts

Unread postPosted: 21 Feb 2020, 18:53
by sprstdlyscottsmn
eloise wrote:I think length and width can be deceiving because they could have different wing shape and vastly different area

That is the entire point of that section, to show how densely packed something is inside its Spot Area (a term used by the Navy for describing the actual amount of space a plane takes in the hangar deck).

eloise wrote:But SPEAR is very small, smaller than a short range air to air missile. And a short range air to air missile only has RCS about 0.03 m2 frontally

if you want to make a general argument that SPEAR should be lower than 0.1 I will listen, but length has little to do with RCS. SPEAR is 7in across, the same size as an AMRAAM and wider than a Sidewinder, and has a large rounded glass nose. The overall design of SPEAR shows no LO considerations. I see no reason for SPEAR to not have the highest RCS betwen itself, the SLAM-ER, and AAMs.

**EDIT** so a perfect circular reflector, which I am assuming the nose of SPEAR is, 7in across is 0.025m^2. I would think total RCS would be no less than twice this to account for edge refractions and surface creep, etc. With this in mind, I am inclined to reduce the RCS or SLAM-ER as it displays LO considerations in its design.

Re: Comparison by Spurts

Unread postPosted: 21 Feb 2020, 23:20
by mozza
sprstdlyscottsmn wrote:Here is the comparison currently. I am working on the F-16 model now.

Strike Fighters 2025_4.pdf


Rafale don't use Damocles pod anymore, he use the Talios pod.

https://www.thalesgroup.com/sites/defau ... S-GB_0.pdf

Re: Comparison by Spurts

Unread postPosted: 21 Feb 2020, 23:22
by wrightwing
eloise wrote:


But SPEAR is very small, smaller than a short range air to air missile. And a short range air to air missile only has RCS about 0.03 m2 frontally

RCS isn't based upon physical size. The shape is the more important factor.

Re: Comparison by Spurts

Unread postPosted: 22 Feb 2020, 00:46
by sprstdlyscottsmn
mozza wrote:
sprstdlyscottsmn wrote:Here is the comparison currently. I am working on the F-16 model now.

Strike Fighters 2025_4.pdf


Rafale don't use Damocles pod anymore, he use the Talios pod.

https://www.thalesgroup.com/sites/defau ... S-GB_0.pdf

Thanks!

Re: Comparison by Spurts

Unread postPosted: 22 Feb 2020, 01:01
by madrat
I don't think Talios is decommissioned. Damocles supplanted - not eliminates - the Talios, just as Talios did the same to the first generation pod.

Re: Comparison by Spurts

Unread postPosted: 22 Feb 2020, 04:40
by marsavian
Originating thread

viewtopic.php?f=55&t=25735

Re: Comparison by Spurts

Unread postPosted: 22 Feb 2020, 05:10
by eloise
sprstdlyscottsmn wrote:if you want to make a general argument that SPEAR should be lower than 0.1 I will listen, but length has little to do with RCS. SPEAR is 7in across, the same size as an AMRAAM and wider than a Sidewinder, and has a large rounded glass nose. The overall design of SPEAR shows no LO considerations. I see no reason for SPEAR to not have the highest RCS betwen itself, the SLAM-ER, and AAMs.
**EDIT** so a perfect circular reflector, which I am assuming the nose of SPEAR is, 7in across is 0.025m^2. I would think total RCS would be no less than twice this to account for edge refractions and surface creep, etc. With this in mind, I am inclined to reduce the RCS or SLAM-ER as it displays LO considerations in its design.

Except for faceted window, there are two problems with SLAM-ER
Saudi Arabia f-15s e   AGM-84H Standoff Land Attack Missiles-Expanded Response (SLAM-ER), 973 AGM-154C Joint Stand Off Weapons (JSOW), 400 AGM-84L Harpoon Block II missiles, 1000 GBU-39B Small Diameter Bomb.jpg

Firstly, the missile body is a pure cylinder, that is the perfect condition for creeping wave return. True VLO missiles such as Jassm, Jsow, Nsm never have pure cylinder body
Image
Secondly, it has four big tail fins, so they made up 4 right angle reflectors. On VLO missile such as Jsow the corner is acute and on Jassm, the horizontal fin is very small
Capture.PNG


Spear isn't fully cylindrical and the 3 small tail fins made obtuse angles
spear-1.006-640x360.jpg

Re: Comparison by Spurts

Unread postPosted: 22 Feb 2020, 15:05
by sprstdlyscottsmn
I see what you are saying. Per my previous post about the SPEAR window, I can't justify it going lower that 0.05, but you have a decent argument that SLAM-ER should be in the same class, not half the size.

Re: Comparison by Spurts

Unread postPosted: 23 Feb 2020, 03:36
by eloise
sprstdlyscottsmn wrote:I see what you are saying. Per my previous post about the SPEAR window, I can't justify it going lower that 0.05, but you have a decent argument that SLAM-ER should be in the same class, not half the size.

Another detail I want to suggest is
Stuart said the company is evaluating multiple sources for the aft actuator solution and also for the new rocket motor design that, Jane's understands, is expected to deliver an engagement speed that is double that of the current AARGM. "Our assessment is that there are propulsion options out there that are high TRL and can quickly transition into a production scenario to meet the USN's timelines," he said.

While the propulsion type has yet to be decided, a ramjet solution has not been discounted. "The current Orbital ATK design concept is not a ramjet, but it certainly doesn't remove that potential. However, it will be the USN and its requirements office that make the final decision on where they want to go with propulsion," he said.

'Increased Survivability' is built into the AARGM ER requirement, although Stuart declined to comment on the specifics of the Orbital ATK solution, noting only that "speed is in the equation. We're going double the range in about the same amount of time, and you have to increase speed to achieve that; so speed in and of itself is an improvement to survivability. There are other aspects of our design solution that improve survivability, but these are not releasable".

https://www.janes.com/article/71285/orb ... gn-concept
AARGM is mach 2 - 150 km missile, So if AARGM-ER can fly 300 km in the same amount of time, I think it will reach Mach 4 (or have much higher cruising speed than AARGM, but AARGM-ER doesn't have ramjet motor so Iam more inclined that it is much faster)

Re: Comparison by Spurts

Unread postPosted: 23 Feb 2020, 05:23
by sprstdlyscottsmn
eloise wrote:
sprstdlyscottsmn wrote:I see what you are saying. Per my previous post about the SPEAR window, I can't justify it going lower that 0.05, but you have a decent argument that SLAM-ER should be in the same class, not half the size.

Another detail I want to suggest is
Stuart said the company is evaluating multiple sources for the aft actuator solution and also for the new rocket motor design that, Jane's understands, is expected to deliver an engagement speed that is double that of the current AARGM. "Our assessment is that there are propulsion options out there that are high TRL and can quickly transition into a production scenario to meet the USN's timelines," he said.

While the propulsion type has yet to be decided, a ramjet solution has not been discounted. "The current Orbital ATK design concept is not a ramjet, but it certainly doesn't remove that potential. However, it will be the USN and its requirements office that make the final decision on where they want to go with propulsion," he said.

'Increased Survivability' is built into the AARGM ER requirement, although Stuart declined to comment on the specifics of the Orbital ATK solution, noting only that "speed is in the equation. We're going double the range in about the same amount of time, and you have to increase speed to achieve that; so speed in and of itself is an improvement to survivability. There are other aspects of our design solution that improve survivability, but these are not releasable".

https://www.janes.com/article/71285/orb ... gn-concept
AARGM is mach 2 - 150 km missile, So if AARGM-ER can fly 300 km in the same amount of time, I think it will reach Mach 4 (or have much higher cruising speed than AARGM, but AARGM-ER doesn't have ramjet motor so Iam more inclined that it is much faster)

That one I will disagree with on the principles of physics. It is pure speculation that it has the same time of flight. Even if we say the new missile has half the drag of the old missile, it would only have 41% more speed/range for the same thrust/time/fuel mass. To have twice the speed even with half the drag coefficient would be 2 times the thrust, which would need 2 times the fuel. AARGM ER is not a larger missile than AARGM and has the same guidance and warhead, so there is nor feasible way for it to carry twice the fuel.

Re: Comparison by Spurts

Unread postPosted: 23 Feb 2020, 07:08
by eloise
sprstdlyscottsmn wrote:That one I will disagree with on the principles of physics. It is pure speculation that it has the same time of flight. Even if we say the new missile has half the drag of the old missile, it would only have 41% more speed/range for the same thrust/time/fuel mass. To have twice the speed even with half the drag coefficient would be 2 times the thrust, which would need 2 times the fuel. AARGM ER is not a larger missile than AARGM and has the same guidance and warhead, so there is nor feasible way for it to carry twice the fuel.

But AARGM-ER is a larger missile with wider diameter than AARGM
AARGM rocket motor diameter is 254 mm
AARGM rocket motor diameter is 290 mm
If the length of the rocket motor section is equally long, AARGM-ER will carry 29% more rocket fuel, but they removed the mid body wing/actuator section, so I think it is feasible for it to carry twice the fuel load.

17EBD85B-127B-4B3D-A689-6AE3B6866645.jpeg

E2987019-EF1C-48EA-952B-18A4C75E5804.jpeg

17CAF9BF-8EFA-49EF-A8C7-D4199B97031E.png

A165AE79-3526-47FD-A0E8-634A60EBA5E0.png

Re: Comparison by Spurts

Unread postPosted: 23 Feb 2020, 15:42
by sprstdlyscottsmn
The new propulsion section would need to be over 50% longer than the old one. Looking at the space between the find on the old one, and the removed control section, that might just be it.

Thank you for taking the time to go over your evidence with me on this, as it ended up causing my rebuttal to line up with your argument. Provided, of course, that the missile has half the drag coefficient by ditching the big fore wings.

Re: Comparison by Spurts

Unread postPosted: 23 Feb 2020, 18:46
by eloise
sprstdlyscottsmn wrote:The new propulsion section would need to be over 50% longer than the old one. Looking at the space between the find on the old one, and the removed control section, that might just be it.

Thank you for taking the time to go over your evidence with me on this, as it ended up causing my rebuttal to line up with your argument. Provided, of course, that the missile has half the drag coefficient by ditching the big fore wings.

Thank you for the great explaination too.
By the way, when we talk about mach 2 speed for AARGM and mach 4 speed for AARGM-ER, is it top speed or average speed?

Re: Comparison by Spurts

Unread postPosted: 23 Feb 2020, 18:50
by juretrn
Sprts,

you're the best! :notworthy: :notworthy:

Re: Comparison by Spurts

Unread postPosted: 23 Feb 2020, 20:04
by sprstdlyscottsmn
If fired from a good cruising altitude with a loft profile then there will not be as much speed lost. I treat it as an average speed for that reason. I do not go into as much investigation for the AG missiles as I treat them as fairly static, as their targets are static.

Re: Comparison by Spurts

Unread postPosted: 24 Feb 2020, 10:32
by eloise
sprstdlyscottsmn wrote:If fired from a good cruising altitude with a loft profile then there will not be as much speed lost. I treat it as an average speed for that reason. I do not go into as much investigation for the AG missiles as I treat them as fairly static, as their targets are static.

I find that Kh-15 has very similar kinematic specs with AARGM-ER
Kh-15 max range is 300 km, AARGM-ER max range is also 300 km
1ja1o.jpg

t3ULL.jpg

1.PNG

Kh-15 can climb to 40 km and reach Mach 5 in the final dive at target, I don't know if AARGM-ER is capable of the same thing, so I look closer
Kh-15 propellant is 44% of its length, Kh-15 is 478 cm long and 45.5 cm in diameter so the propellant volume is 3.42×10^5 cubic centimeter
AARGM-ER propellant is 49.6% of its length, AARGM-ER is 410 cm long and 29 cm in diameter so the propellant volume is 1.34×10^5 cubic centimeter
So Kh-15 carries 2.55 times more rocket propellant than AARGM-ER. But, Kh-15 diameter is 45.5 cm while AARGM-ER diameter is 29 cm so the cross section area of Kh-15 is 2.46 times greater than AARGM-ER. Because form drag is proportional to cross section area, AARGM-ER can reach the same speed as Kh-15 even though it carries less propellant. Is that reasonable ?

Re: Comparison by Spurts

Unread postPosted: 24 Feb 2020, 14:25
by sprstdlyscottsmn
the "drag is proportional to cross sectional area" is a bit of a misnomer, but it can be useful for first order approximations.

Re: Comparison by Spurts

Unread postPosted: 25 Feb 2020, 03:30
by eloise
sprstdlyscottsmn wrote:Here is the comparison currently. I am working on the F-16 model now.

Strike Fighters 2025_4.pdf

I have another question about these specs of these air to air missiles
Why is the boost time of MiCA, R-77-1 and AIM-9X so long?
Mica can boost almost as long as the sustain time of Meteor?

Re: Comparison by Spurts

Unread postPosted: 25 Feb 2020, 15:54
by sprstdlyscottsmn
eloise wrote:I have another question about these specs of these air to air missiles
Why is the boost time of MiCA, R-77-1 and AIM-9X so long?
Mica can boost almost as long as the sustain time of Meteor?

Those missiles are using single impulse motors, "boost-only", and have no sustaining charge. I try to assume this is the default motor condition of AAMs unless it is specifically stated otherwise or the listed performance specs are unobtainable otherwise.

Also, the Sustain time of the meteor is the minimum time, and it CAN sustain for ten times as long by throttling back.

Re: Comparison by Spurts

Unread postPosted: 25 Feb 2020, 17:01
by eloise
sprstdlyscottsmn wrote:Those missiles are using single impulse motors, "boost-only", and have no sustaining charge. I try to assume this is the default motor condition of AAMs unless it is specifically stated otherwise or the listed performance specs are unobtainable otherwise.

Also, the Sustain time of the meteor is the minimum time, and it CAN sustain for ten times as long by throttling back.

I get that, but except for Meteor and AIM-120D I feel like the boost and sustain time of the others are too long
I mean AIM-120 can boost for 7 seconds but MICA can boost for 20 seconds?
4EBE0DEA-74AC-4DE9-BF52-C8EE54D3784E.jpeg

C6ABAF22-16AC-4B89-BED7-38E397876D10.jpeg

Re: Comparison by Spurts

Unread postPosted: 25 Feb 2020, 17:20
by sprstdlyscottsmn
eloise wrote:I get that, but except for Meteor and AIM-120D I feel like the boost and sustain time of the others are too long
I mean AIM-120 can boost for 7 seconds but MICA can boost for 20 seconds?

AIM-120 boost only for 8s, not 7, and at nearly 4,500lbt. It gets to Mach 4 in about 3nm. It uses loft in order to get its range.

MICA has a 20s motor, yes, but with only 1,485lbt it takes 7nm to reach Mach 4. Even with loft it does not come anywhere close to the range of the AIM-120D because of the high drag fins on a lightweight missile (see it's crazy high Dogfight score?). I did not like what I had to do with the MICA, but it was the only way I found to get the kind of range it is reported to have.

My missile model requires me to make a LOT of assumptions and I have to play with a lot of parameters to get the reported performance, since motor information is generally non-existant.

Re: Comparison by Spurts

Unread postPosted: 25 Feb 2020, 17:43
by sprstdlyscottsmn
for example, if I change the MICA motor to 8s at 3700lbt and increase loft to 25 degrees (same burn time and loft as AIM-120D) it actually loses range and it's speed goes to over Mach 5 (in 4nm).

If I leave loft alone and change it to 2s Boost at ~5600lbt and 10s Sustain at ~1800lbt the top speed goes up a little but it still solidly in the Mach 4 range, but it still loses flight range. In effect, with a 20deg loft the MICA needs to still be doing Mach 4 from 9NM on to reach 80km flight range in under 180s. No matter how I slice it, it needs 20s of motor burn time to get there. Even 2s boost and 17s sustain wont reach the range needed.

Don't get hung up on the terms "boost" and "sustain". Sustain only applies if there are two thrust levels. For a given ISP and Fuel Weight, there is only so much "delta V" available. The use of single pulse or duel pulse thrust levels only change HOW the delta V is applied.

Case in point, two 20s motors for MICA, with a "boost/sustain" thrust ratio of 3, a 2s/18s boost/sust time split results in the boost phase burning 12.5% o the fuel per second while the sustain phase burns 4.2% per second. a 20 "Boost" burns 5.0% of fuel per second. Both provide 29,700lbt-s (110lb motor with 270 ISP)

Re: Comparison by Spurts

Unread postPosted: 25 Feb 2020, 17:56
by eloise
I see your reasoning but I think the range value on internet may not be correct.
For MiCA I think you can calculate the motor burn time from this video

Re: Comparison by Spurts

Unread postPosted: 25 Feb 2020, 18:34
by sprstdlyscottsmn
That video suggests one of three things

SL version of MICA uses a different motor entirely (unlikely)
MICA has a ~3.5s Boost only motor (unlikely)
MICA has ~3.5s boost phase and a much lower thrust sustain phase (most likely)

" On October 23, 2008, 15:30, at CELM, Biscarosse (Landes), a VL MICA missile successfully performed the last of its 14 test firings meaning it is now ready for mass production. The target drone was flying at low level, over the sea, 12 km away; despite this distance, MICA, equipped with an active radar seeker, locked on the target and shot it down."

So we know a surface launch against a low altitude target is engageable from 12km (6.5nm).

Let's look at option 2 first.
a 3.5 motor burn time would do this, but the final speed would be a mere 0.36M.

Option 3
a 3.5s boost and 16.5s sustain (to stay with my 20s total burn time) with a 5:1 thrust ratio increases final speed to 0.83M

Option 2 for comparison test
missile hits Mach 5.75 but is down below Mach 1 by 24nm

Option 3 for comparison test
missile hits 3.77 Mach and loses 0.1nm of flight range. This is consistent with the MICA being a "Mach 4 missile with 80km range"
If I change the boost thrust ratio to 3 top speed becomes 3.99 Mach and range increases by 0.4nm, also consistent with "M4 80km"

After watching that video and running numbers I see reason to alter the MICA motor to Option 3 with a 3:1 thrust ratio.

Re: Comparison by Spurts

Unread postPosted: 26 Feb 2020, 04:15
by eloise
sprstdlyscottsmn wrote:That video suggests one of three things

SL version of MICA uses a different motor entirely (unlikely)
MICA has a ~3.5s Boost only motor (unlikely)
MICA has ~3.5s boost phase and a much lower thrust sustain phase (most likely)

" On October 23, 2008, 15:30, at CELM, Biscarosse (Landes), a VL MICA missile successfully performed the last of its 14 test firings meaning it is now ready for mass production. The target drone was flying at low level, over the sea, 12 km away; despite this distance, MICA, equipped with an active radar seeker, locked on the target and shot it down."

So we know a surface launch against a low altitude target is engageable from 12km (6.5nm).

Let's look at option 2 first.
a 3.5 motor burn time would do this, but the final speed would be a mere 0.36M.

Option 3
a 3.5s boost and 16.5s sustain (to stay with my 20s total burn time) with a 5:1 thrust ratio increases final speed to 0.83M

Option 2 for comparison test
missile hits Mach 5.75 but is down below Mach 1 by 24nm

Option 3 for comparison test
missile hits 3.77 Mach and loses 0.1nm of flight range. This is consistent with the MICA being a "Mach 4 missile with 80km range"
If I change the boost thrust ratio to 3 top speed becomes 3.99 Mach and range increases by 0.4nm, also consistent with "M4 80km"

After watching that video and running numbers I see reason to alter the MICA motor to Option 3 with a 3:1 thrust ratio.

I get your point but I feel uneasy because this video shows very quick burn motor
I screenshot some parts of it, we are lucky that there is a time indicator on the top of the video
The boost motor start at 13:52:31:319 and end at 13:52:34:339 so the boost phase operate for 3 seconds give or take
Mica flame out and the smoke trail stop at 13:52:36:739 so the sustain phase burn for 2.3 seconds or does motor flame stop glowing in the sustain phase?
1.PNG

1.5.PNG

2.PNG

Re: Comparison by Spurts

Unread postPosted: 26 Feb 2020, 04:40
by eloise
I also find a video of AIM-132 ASRAAM


The motor burn bright start at 0:18 then shut down fully at 0:22 so I think it is a 4 seconds full boost motor instead of 2 seconds boost and 20 seconds sustain, is that possible?

1.PNG

1.5.PNG

Re: Comparison by Spurts

Unread postPosted: 26 Feb 2020, 16:17
by sprstdlyscottsmn
In short, no. No missile is going to have anything even close to medium range with 4s or less of total thrust. The only plausible answer is that the sustain thrust does not produce enough "glow" for the video capture. The AIM-132 was supposed to be a "BVR" missile with more range than Sidewinder, that was the whole point.

Re: Comparison by Spurts

Unread postPosted: 26 Feb 2020, 18:32
by eloise
sprstdlyscottsmn wrote:In short, no. No missile is going to have anything even close to medium range with 4s or less of total thrust.

Can you please explain to me why can't they do that? :(
AIM-120C- motor burn for 7.77 seconds so shouldn't AIM-132 burning for 4 seconds have about 51% the range? The thrust is lower but AIM-132 is smaller too. And what if the burn time is low but the thrust is very high? similar to a gun

Re: Comparison by Spurts

Unread postPosted: 26 Feb 2020, 19:35
by sprstdlyscottsmn
AIM-120 achieves phenomenal range off a relatively short, but very powerful, burn combined with a long, thin body and small fins that provide very little drag and a high lofting trajectory. By the time the motor of the AIM-120 burned out the missile is already over 5,000ft higher than the launching aircraft and traveling 25 degrees up into thin air at Mach 4.22.

The AIM-132 has the same diameter as the AIM-120 but it shorter, it has a lower fineness ratio which increases drag. It has only small fins on the rear, so the form drag from fins is smaller, but that means most the lift is coming from the body, which comes with more drag.

If I take the AIM-32 to a single 4s pulse... and acknowledge that it must have datalink for LOAL capability and as such CAN utilize a loft profile (lofting was not an assumption I was allowing before), and reduce the rocket motor mass by 18lb (it was nearly 45% of the missile weight before) I get a 4.75M top speed and a few tenths of a nm more range in the same time. I see it is performing a sharp pull instead of a ballistic curve, so the loft I gave it may be non-optimal for the time of flight limit.

So, the AIM-132 might have a 4s motor, but no way can MICA make twice the range on the same burn, not with all that fin.

Re: Comparison by Spurts

Unread postPosted: 27 Feb 2020, 02:59
by eloise
sprstdlyscottsmn wrote:AIM-120 achieves phenomenal range off a relatively short, but very powerful, burn combined with a long, thin body and small fins that provide very little drag and a high lofting trajectory. By the time the motor of the AIM-120 burned out the missile is already over 5,000ft higher than the launching aircraft and traveling 25 degrees up into thin air at Mach 4.22.

The AIM-132 has the same diameter as the AIM-120 but it shorter, it has a lower fineness ratio which increases drag. It has only small fins on the rear, so the form drag from fins is smaller, but that means most the lift is coming from the body, which comes with more drag.

If I take the AIM-32 to a single 4s pulse... and acknowledge that it must have datalink for LOAL capability and as such CAN utilize a loft profile (lofting was not an assumption I was allowing before), and reduce the rocket motor mass by 18lb (it was nearly 45% of the missile weight before) I get a 4.75M top speed and a few tenths of a nm more range in the same time. I see it is performing a sharp pull instead of a ballistic curve, so the loft I gave it may be non-optimal for the time of flight limit.

So, the AIM-132 might have a 4s motor, but no way can MICA make twice the range on the same burn, not with all that fin.

Thank you,now I understand
Any how, I have just double check and the diameter of AIM-132 is 165 mm compared to 180 mm of AIM-120, it has LOAL ability but unfortunately no datalink.
Do you think Peregrine can match Mica range? Peregrine is about 1.8m (6ft) long and 68kg (150lb)
Capture.PNG

mica.jpg

Re: Comparison by Spurts

Unread postPosted: 27 Feb 2020, 04:57
by sprstdlyscottsmn
eloise wrote:
Any how, I have just double check and the diameter of AIM-132 is 165 mm compared to 180 mm of AIM-120, it has LOAL ability but unfortunately no datalink.
Do you think Peregrine can match Mica range? Peregrine is about 1.8m (6ft) long and 68kg (150lb)

AIM-132 MOTOR is 165mm, the AIM-120 BODY is 180mm. They both are a 7in, 180mm body. AIM-132 has to have a one-way datalink in order to do LOAL doesn't it?

Peregrine (and CUDA before that) hare "HalfRAAM" missile with two thirds of the motor of an AMRAAM. They are typically HTK missiles and as such replace the warhead space with more fuel. Those can have tremendous range potential, somewhere between MICA and AMRAAM I expect. Tomorrow I will check my missile sim to see if I had modeled a Peregrine before. A missile that small would do best with a low and slow burn.

Re: Comparison by Spurts

Unread postPosted: 27 Feb 2020, 05:31
by mozza
Just a little add:MICA is part of the SPECTRA suite since the IR ones on the wingtips act as an IRST during the flight and their sensors are "fused" in SPECTRA, (MICA is also HOBS btw)
So maybe the EO/IR part need to be updated.
And about your debate, i don't know why you think that long fin on a missile = big drag and = less range? If it's true why Raytheon and MBDA do that ? Maybe it's more complex than that...?

Re: Comparison by Spurts

Unread postPosted: 27 Feb 2020, 06:53
by eloise
sprstdlyscottsmn wrote:AIM-132 MOTOR is 165mm, the AIM-120 BODY is 180mm. They both are a 7in, 180mm body. AIM-132 has to have a one-way datalink in order to do LOAL doesn't it?.

I think the diameter for missile body in both case, AIM-132 is visibly smaller than Meteor and Meteor and AIM-120 have the same diameter. Missiles doesn't need datalink for LOAL if they have automatic target acquisition capabilities
D3569F28-F76B-419D-900E-B5DA5839BC5F.jpeg

BA657A03-1863-45A1-9296-3F856D716ED9.jpeg

Re: Comparison by Spurts

Unread postPosted: 27 Feb 2020, 08:00
by eloise
mozza wrote:Just a little add:MICA is part of the SPECTRA suite since the IR ones on the wingtips act as an IRST during the flight and their sensors are "fused" in SPECTRA, (MICA is also HOBS btw)
So maybe the EO/IR part need to be updated.
And about your debate, i don't know why you think that long fin on a missile = big drag and = less range? If it's true why Raytheon and MBDA do that ? Maybe it's more complex than that...?

MICA was added to Spectra because the IIR component of FSO is currently removed so the MICA sensor will provide some interim capabilities until a new IIR sensor is added to FSO, but it cant match capabilities of true IRST due to cooling and aperture limitation
Big wing add more lift, so your missile is more maneuverable at high altitude or low speed, but big wings also add more drag

Re: Comparison by Spurts

Unread postPosted: 27 Feb 2020, 13:33
by sferrin
sprstdlyscottsmn wrote:Peregrine (and CUDA before that) hare "HalfRAAM" missile with two thirds of the motor of an AMRAAM.

Peregrine is Raytheon. CUDA is LM. (CUDA is not dead BTW.)


sprstdlyscottsmn wrote:They are typically HTK missiles and as such replace the warhead space with more fuel.

Peregrine has a blast/frag warhead.

Re: Comparison by Spurts

Unread postPosted: 27 Feb 2020, 15:05
by sprstdlyscottsmn
sferrin wrote:Peregrine has a blast/frag warhead.

I was unaware of that, I assumed it was just like the CUDA.

Re: Comparison by Spurts

Unread postPosted: 27 Feb 2020, 16:25
by eloise
sferrin wrote:Peregrine is Raytheon. CUDA is LM. (CUDA is not dead BTW.)

I heard it become a candidate for M-Rad
1.PNG

2.PNG

Re: Comparison by Spurts

Unread postPosted: 17 Mar 2020, 20:27
by sprstdlyscottsmn
Working on the thrust model for the F-16. Having low speed to max speed accelerations for ten thousand foot increments is so helpful. Matching speed, fuel, and distance for the given acceleration time within +- 2% plus getting to see where it's like "Okay, .67 to 1.83 happens pretty smoothly, 1.83 to 2.02 takes almost as long, doubles the fuel, and more than doubles the distance"

The HAF manual provides so much information. The biggest thing missing is the stores carriage/employment limits that I have only noticed on the F-15-1 so far.

Re: Comparison by Spurts

Unread postPosted: 17 Mar 2020, 23:57
by energo
sprstdlyscottsmn wrote:"Okay, .67 to 1.83 happens pretty smoothly, 1.83 to 2.02 takes almost as long, doubles the fuel, and more than doubles the distance"


Probably old news and not very relevant, but one RNoAF F-16A pilot once told me that pushing Mach 1.6 was like "hitting a wall". It wen't slowly from there. Mostly due to the inlet, I was led to believe. Most RNoAF pilots I've talked to have barely had it much past Mach 1.9 in FCSs. As one said, to the effect of: "I couldn't bother trying Mach 2. Not enough fuel!" This was way before the -220E, so it might not be accurate today.

Re: Comparison by Spurts

Unread postPosted: 18 Mar 2020, 00:03
by sprstdlyscottsmn
energo wrote:
sprstdlyscottsmn wrote:"Okay, .67 to 1.83 happens pretty smoothly, 1.83 to 2.02 takes almost as long, doubles the fuel, and more than doubles the distance"


Probably old news and not very relevant, but one RNoAF F-16A pilot once told me that pushing Mach 1.6 was like "hitting a wall". It wen't slowly from there. Mostly due to the inlet, I was led to believe. Most RNoAF pilots I've talked to have barely had it much past Mach 1.9 in FCSs. As one said, to the effect of: "I couldn't bother trying Mach 2. Not enough fuel!" This was way before the -220E, so it might not be accurate today.

I'm analyzing the -129

Re: Comparison by Spurts

Unread postPosted: 18 Mar 2020, 00:21
by energo
sprstdlyscottsmn wrote:I'm analyzing the -129


Absolutely, keep up the good work! :mrgreen:

Re: Comparison by Spurts

Unread postPosted: 18 Mar 2020, 02:00
by rheonomic
sprstdlyscottsmn wrote:Working on the thrust model for the F-16.

It's probably a shitty model but NASA TP-1538 (PDF) has a static engine model as a function of PLA, Mach, and altitude for an "F-16 like" aircraft. There's also an aero model that might be ok to ~M0.6 or so. There's a MATLAB version of the reduced model the Stevens & Lewis textbook has available here for non-commercial use.

Re: Comparison by Spurts

Unread postPosted: 07 Apr 2020, 12:07
by eloise
New AIM-120C model in DCS, closer to real life?

Re: Comparison by Spurts

Unread postPosted: 07 Apr 2020, 15:32
by sprstdlyscottsmn
There are a few takeaways from that video.

Aspect: These were head on shots.

Launch conditions: 1.6M from 50,000+ft... hmm, isn't there some Wunderjet that cruises at those kinds of conditions where it was stated it would roughly double launch ranges? Now it is highlighted why. The missiles were able to stay faster for longer in rarified atmosphere.

Target dynamics: The targets were all at high altitude so the missile never had to slow down in thicker air. The targets did not have much time to maneuver either so they did not have the opportunity to generate lateral separation.

Crunching numbers on the three shots

50nm shot, 64s time of flight, actual flight range 40.4nm (target covered the rest)
55nm shot, 74s time of flight, actual flight range 43.9nm
60nm shot, 75s time of flight, actual flight range 45.6nm

Re: Comparison by Spurts

Unread postPosted: 08 Apr 2020, 16:20
by sprstdlyscottsmn
Update: No update right now. During the midst of all this craziness I am also changing jobs and moving cross country.

Re: Comparison by Spurts

Unread postPosted: 08 Apr 2020, 17:23
by lamoey
sprstdlyscottsmn wrote:Update: No update right now. During the midst of all this craziness I am also changing jobs and moving cross country.


I'm please to hear that you have a job, under the current climate.

Re: Comparison by Spurts

Unread postPosted: 09 Apr 2020, 02:42
by eloise
sprstdlyscottsmn wrote:Update: No update right now. During the midst of all this craziness I am also changing jobs and moving cross country.

It is scary, I hope US find out the cure soon

sprstdlyscottsmn wrote:There are a few takeaways from that video.

Aspect: These were head on shots.

Launch conditions: 1.6M from 50,000+ft... hmm, isn't there some Wunderjet that cruises at those kinds of conditions where it was stated it would roughly double launch ranges? Now it is highlighted why. The missiles were able to stay faster for longer in rarified atmosphere.

Target dynamics: The targets were all at high altitude so the missile never had to slow down in thicker air. The targets did not have much time to maneuver either so they did not have the opportunity to generate lateral separation.

Crunching numbers on the three shots

50nm shot, 64s time of flight, actual flight range 40.4nm (target covered the rest)
55nm shot, 74s time of flight, actual flight range 43.9nm
60nm shot, 75s time of flight, actual flight range 45.6nm

Thank you

Re: Comparison by Spurts

Unread postPosted: 18 May 2020, 16:59
by sprstdlyscottsmn
Okay, so now I do have an update! I have "finalized" my F-16V model. Now on to mission work.

Re: Comparison by Spurts

Unread postPosted: 19 May 2020, 02:35
by sprstdlyscottsmn
I swear, 100 hours to make the model, and in 5 hours after that I have have the analysis work done.

Re: Comparison by Spurts

Unread postPosted: 19 May 2020, 02:44
by eloise
sprstdlyscottsmn wrote:I swear, 100 hours to make the model, and in 5 hours after that I have have the analysis work done.

I knew your model take very long to make but holy **** 100 hours, I'm deeply impressed.

Re: Comparison by Spurts

Unread postPosted: 04 Jul 2020, 03:23
by sprstdlyscottsmn
So, I made a statement about 5 hours getting what I estimated to be half of the analysis work done. I took the time to count the rest. 280 minutes to finish, or just over 4.5 hours. The Viper is finished. On to the Super Hornet and the last thing I have a manual for.

Strike Fighters 2025_5.pdf
(1.07 MiB) Downloaded 33 times

Re: Comparison by Spurts

Unread postPosted: 04 Jul 2020, 05:19
by 35_aoa
energo wrote:
Probably old news and not very relevant, but one RNoAF F-16A pilot once told me that pushing Mach 1.6 was like "hitting a wall". It wen't slowly from there. Mostly due to the inlet, I was led to believe. Most RNoAF pilots I've talked to have barely had it much past Mach 1.9 in FCSs. As one said, to the effect of: "I couldn't bother trying Mach 2. Not enough fuel!" This was way before the -220E, so it might not be accurate today.


With a centerline tank/pylons (or in a -B) yeah, I remember 1.6 being about where the ride got rough and things slowed down. It's been a while, but I remember a completely slick -A moving pretty steadily up to about 1.8 and then hitting the proverbial brick wall. I know one guy who got it to 1.99......nobody who bested 2.0, though I know it has happened plenty of times.....I believe an A was lost in the early years exceeding the mach limit (memory is fading now and don't have a -1 to reference, but I seem to remember 2.01 or 2.02M being the lim) in a dive, when the engine turbine section (or something of that nature) disintegrated violently and ripped the airplane apart.....maybe gums remembers that tale that was told to me many many years later when learning to fly the same old bird.

Re: Comparison by Spurts

Unread postPosted: 04 Jul 2020, 13:41
by sprstdlyscottsmn