What i understand the monopulse seeker is not a integral method.
But anyway, if they try to reply ground hugging, at least increase the chances in percent to a missile hit and go towards at low level target and the proximity fuze work.
The missile pass close and does not explode side side of target
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The two motors total impulse are almost identical
Ie thrust * time.
One is higher thrust and less burn time
One is lower thrust and higher burn time
Does 20s vs 27-30s matters?
Maybe, Maybe not, depending on the scenario.
But the delta V, ie speed gained, should be mostly equal.
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Do we have an actual source for this or are you quoting DCS figures?
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Yes we do. Extremely detailed in fact. Unfortunately not able to share it though.
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If the Mk 60 motor has a lower burn time and higher thrust it would be more useful in-game against fighter sized targets at medium ranges I presume… but what I said earlier is true only a hundred or so motors were built and primarily for the AIM-54A models. The AIM-54C came standard with the Mk47 mod 1.
Quick question, are developers aware of too much drag from phoenix and benefit of base drag reduction from long burning motors. Some players had done test in War Thunder and their footage shows Aim54 is pulled behind by enormous drag upon launch but before ignition, where as historical footage shows they don’t suffer from this.
In game footage, Aim-54 moves backwards for half fuselage length of F-14 after launch, until motor ignites and they start accelerating forwards.
Historical footage of Aim54, it does not experience massive drag and does not move backwards significantly after launch and before ignition.
These planes are not accelerating with full burner or 100% throttle, they are cruising so the “missile fall behind” is not due to plane itself accelerating away from missile.
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Those Tomcats are accelerating in-game whereas the F-14s in the test video are not.
i found some bugs, i will post
If you look at 2:03 of that video, these Tomcats are clearly cruising at 78% throttle, not accelerating with full AB or 100% power.
The test was meant to eliminate all factors unrelated to the missile, that includes eliminating the acceleration of Tomcat.
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That’s what I said.
I think you misunderstood or did not remember what said previously. You said Tomcats in game were accelerating, and I said the in-game test video clearly shows they are not accelerating, sometimes even decelerating.
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If that is the case, do we know if the real world video of the Tomcats shows them maintaining a steady speed?
We don’t “know” as it is not included in the video however given that it is a test of the missile’s performance, would it not be more logical to assume the planes are maintaining a set speed so as to exclude that variable from the test?
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This reply is talking about the IRL (in real life) footage of Tomcat launching Aim-54 I posted above: The AIM-54 Phoenix missile - Technology, History and Performance - #1106 by SE_8749236
The bottom line is, for testing purpose, the Tomcat IRL is either accelerating or maintaining current speed.
So let’s evaluate each case.
- Tomcat in IRL footage is accelerating, and the Aim-54 is not falling behind by significant amount after launch but before ignition.
This means Aim-54 has vastly superior drag coefficient to the point that it is not losing any speed before ignition.
Conclusion: Aim54 in game has too much drag - Tomcat in IRL footage is maintaining speed,and the Aim-54 is not falling behind by significant amount after launch but before ignition.
This means Aim-54 has some drag but not enough to cause it fall behind by 10 meters during its ignition delay.
Conclusion: Aim54 in game has too much drag
So it doesn’t matter, Aim-54 in game has too much drag either way.
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This reply is talking about the in game footage of Tomcat launching Aim-54 I posted above: The AIM-54 Phoenix missile - Technology, History and Performance - #1106 by SE_8749236
TL;DR: The Aim-54 in game is estimated to have a drag coefficient of ~4.25, a typical amateur rocket IRL has drag coefficient of 1 or less.
Using in game footage and kinematics, we can estimate the drag force that the Aim54 is receiving.
With aircraft as reference frame, Aim-54 starts at 0m/s and displacement of 0.
After launch and it starts fall behind, when ignition, it was displaced backwards by ~10 meters.
I’ll calculate 5 meters displacement as well in case I’m over estimating the distance it moved backwards.
10m:
Using d = v1t + 0.5at^2, you get:
10m = 00.5s + 0.5*(a*(0.5s)^2
10m = 0.5*(a*(0.25s^2)
a = 10m / 0.5 / 0.25s^2 = 10 * 2 * 4
a = 80m/s^2
F=ma, and let’s use the lighter Aim54A, m=443kg.
F = 443 * 80 = 35440N of force.
This is clearly an overestimation, since this is more than twice the thrust of Aim-54.
5m:
Using d = v1t + 0.5at^2, you get:
5m = 00.5s + 0.5*(a*(0.5s)^2
5m = 0.5*(a*(0.25s^2)
a = 5m / 0.5 / 0.25s^2 = 5 * 2 * 4
a = 40m/s^2
F=ma, and let’s use the lighter Aim54A, m=443kg.
F = 443 * 40 = 17720N of force.
This is still more than the thrust of rocket motor.
Perhaps base drag reduction is already implemented.
I did calculation wth 4m, since it can’t possibly have displacement less than 4 meters since the missile clearly moved at least its body length after launch but before ignition.
4m:
Using d = v1t + 0.5at^2, you get:
4m = 00.5s + 0.5*(a*(0.5s)^2
4m = 0.5*(a*(0.25s^2)
a = 4m / 0.5 / 0.25s^2 = 4 * 2 * 4
a = 32m/s^2
F=ma, and let’s use the lighter Aim54A, m=443kg.
F = 443 * 32 = 14176N of force.
For comparison, Aim54’s rocket motor in game has 14350N of force.
This yield a net force of 174N, which translates to ~0.4m/s^2 of acceleration, or 1.44km/h per second.
If base drag reduction is not modeled b=ub gane, Aim-54 in game shouldn’t accelerate noticeably at all. Thus base drag reduction is likely modeled.
However, the drag is still way too big and it significantly negatively affects Aim-54 after its burn ends.
If we use drag equation we can estimate the drag coefficient of Aim-54:
Launch speed = 337 knots = ~624km/h = ~173m/s
Launch altitude = 31841ft = ~9705m ==> air density = less than 0.4671.
Missile cross section area when nose first (using 0.39m diameter to compensate for fins): ~0.477m^2
Equation: drag = CA0.5pv^2, C = drag coefficient
Assuming drag = 14176N
14176 = C * 0.477 * 0.5 * 0.4671 * 173^2
C = 14176 / (0.477 * 0.5 * 0.4671 * 173^2) = 14176 / 3334
C = ~4.25
That’s a drag coefficient of whopping 4.25, even worse than a bowl with concave side facing towards the air stream.
This doesn’t make sense for a streamlined missile.
Even if you play with the number and get the estimated drag coefficient down to 2, it is still way worse than IRL. Since typical amateur rockets has drag coefficient of 1 or less when not burning.
This means either CxK is not drag coefficient for missiles and it needs to be lowered, or CxK is drag coefficient but War Thunder has bug where missile’s drag coefficient is 4 times (or more) than it was supposed to be.
Early launch tests might have been on low throttle (decelerating) to avoid engine issues due to smoke intake. Can’t rule this out. We do know the drag is too high, but the exact altitudes and speeds and whether accelerating or not is not known.
Doing the equation, V=a.t
10m – 80m/s^230s=2400m/s
5m — 4030= 1200m/s
But the drag reduses the speed, how to calculated how much reduses?
When the changes are live, anybody want to try em out?