Initial Version of Missile-SIM for Performance evaluation - ED Forums
 


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Old 09-09-2018, 08:49 AM   #1
litzj
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Default Initial Version of Missile-SIM for Performance evaluation

http://jaesan-aero.blogspot.com/2018...e-sim-for.html

I planned to make performance evaluation of the missile for its range.

Coefficient of missile should be calculated by CFD (M, AoA)
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Old 09-22-2018, 07:41 AM   #2
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https://jaesan-aero.blogspot.com/201...ssile-sim.html

Recent update : validation for CFD setting for generic missile shape.

Unfortunately, I cannot achieve very precise aerodynamic coefficient due to limitation of CFD computing source





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Old 10-13-2018, 10:42 AM   #3
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Full detail of the Article is here.

https://jaesan-aero.blogspot.com/201...im-part-1.html

As the first study object, AIM-120C is chosen, and the objective of the study is sensitivity analysis for range performance and its optimization. Range of study includes "Rocket parameter", "Launch condition", and "Multi-stage version of CUDA".

This Part 1 will show sensitivity analysis of rocket parameter for AIM-120C baseline missile; Part 2 is optimization of rocket parameters and launch condition for longer range; Part 3 is proposal of AIM-120 sized dual-stage CUDA missile with optimized configuration.

Part 1 : Sensitivity Analysis of AIM-120C

As shown in Fig. 1-1, baseline of AIM-120C is modeled; some part of the data like propellant weight, and burn time are referenced from previous estimation work. Target parameters of the sensitivity are propellant weight, burn-time, ISP, Drag(CD), Lift(CL), and usage of dual-pulse.

Reference launch condition is set as M1.3 at 30000ft, and I assumed missile go straight without altitude change. Range is calculated when speed of the missile is re-decreased as M1.3 (The missile should pursue target having at least M1.3 speed).

As a summary of Sensitivity (M1.3, 30kft)

(1) 1.2 km Range↑, M 0.1 Speed↑ via 1.0 kg↑of Propellant (in given total weight)

(2) 0.67 km Range↑, almost zero Speed change via 1.0 s↑of Burn time (smaller mass-flow)

(3) 0.2 km Range↑, M 0.01 Speed↑ via 1.0 s↑of ISP

(4) 0.65 km Range↑, almost zero Speed change via 1.0 % Drag reduction

(5) almost zero Range, almost zero Speed change via 1.0 % Lift↑(negligible)

(6) 0.4 km Range↑, M 0.02 Speed↓ via 1.0 s increase of Dual pulse interval


Change of Lift is almost negligible for both range and peak speed performance. Higher lift configuration having more, longer, or larger fins is related to maneuverability and stability.
It is natural that increase of some parameters (Propellant, and ISP) are directly proportional to the range and speed increase.

Longer Burn-time and Drag reduction can increase range without change of speed performance.
(Tendency can be changed at different reference condition)

It could be interesting result that increase of Pulse interval can extend range while small decrease of peak speed.

In given hardware specification (weight, propellant, ISP, lift, and drag), longer burn-time and pulse interval are recommended to extend the range of the AIM-120C class missile.

Improvement via optimization will be performed at Part 2; Result of this sensitivity is applied while study for trajectory and launch condition will be conducted







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Old 10-21-2018, 08:49 AM   #4
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I just published update of AIM-120C study using Missile-SIM

https://jaesan-aero.blogspot.com/201...im-part-2.html

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Old 11-09-2018, 12:59 PM   #5
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https://jaesan-aero.blogspot.com/201...-guidance.html




There is real-time plot video for the Missile-SIM (Guidance of Missile with 0.1s time step)
https://www.youtube.com/watch?v=zBjvOfBz3hs&t=5s
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Old 11-11-2018, 03:27 PM   #6
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Very intresting, how accurate are the inital values you've inputed (burn time, the amount of fuel,...) ? Is the amount of thrust produced at different stages taken into account ? And also when it comes to guidance simulation, what exactly is it doing, just guiding the missile to the target or is it also making sure the missile optimizes it's energy consumption ?

Thank you The R-77, MIM-104, Matra S530D, AIM-7M and the S-300 missile performance, can't remember the exact name, are some of the ones I would be most intrested in seeing.

Regards,
Rex.

P.S. : The missile in your tests looks more like an AIM-120B.
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Old 11-16-2018, 12:47 PM   #7
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Quote:
Originally Posted by Rex854Warrior View Post
Very intresting, how accurate are the inital values you've inputed (burn time, the amount of fuel,...) ? Is the amount of thrust produced at different stages taken into account ? And also when it comes to guidance simulation, what exactly is it doing, just guiding the missile to the target or is it also making sure the missile optimizes it's energy consumption ?

Thank you The R-77, MIM-104, Matra S530D, AIM-7M and the S-300 missile performance, can't remember the exact name, are some of the ones I would be most intrested in seeing.

Regards,
Rex.

P.S. : The missile in your tests looks more like an AIM-120B.
Original model is B model, YES, but I cut the edge of the tail fins to fit C model.

Unfortunately, parameters of the missiles were estimated from another reference;
exact value of rocket motor is basically classified.

Still, the simulation is under the development status; some functions providing different thrust for the given stage is configured while optimized control functions are WIP

Thanks for your interest. I will update my SIM result when the new feature is available
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Old 12-28-2018, 01:35 PM   #8
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Did some more testing, for medium to high altitudes the equation you provided is spot on with the performance of the DCS AIM-120C (tested at 40k feet and 15k feet, MiG-31 at mach 1.3, launcher same altitude at mach 1, closing speed mach 2.3), at lower altitudes though it's a little off compared to the performance in game, about 30% ish less calculated range. Though I didn't do enough testing to call that number relevant it's just what I noticed generaly.

So good job ED I guess ? When are the other missiles getting tuned ? The MIM-104, the MIM-23, the 48H6E2 and the 5V55,...

EDIT : While this data is very nice and probably accurate, it doesn't really fit public data, which makes me wonder why. Now of course the easy explanation is that the public numbers are wrong or fake but it's the "easy" explanation. Maybe the engine parameters are off, if anyone has some inputs on that it would be great .
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Last edited by Rex854Warrior; 12-28-2018 at 01:45 PM.
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Old 12-28-2018, 11:52 PM   #9
litzj
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Quote:
Originally Posted by Rex854Warrior View Post
Did some more testing, for medium to high altitudes the equation you provided is spot on with the performance of the DCS AIM-120C (tested at 40k feet and 15k feet, MiG-31 at mach 1.3, launcher same altitude at mach 1, closing speed mach 2.3), at lower altitudes though it's a little off compared to the performance in game, about 30% ish less calculated range. Though I didn't do enough testing to call that number relevant it's just what I noticed generaly.

So good job ED I guess ? When are the other missiles getting tuned ? The MIM-104, the MIM-23, the 48H6E2 and the 5V55,...

EDIT : While this data is very nice and probably accurate, it doesn't really fit public data, which makes me wonder why. Now of course the easy explanation is that the public numbers are wrong or fake but it's the "easy" explanation. Maybe the engine parameters are off, if anyone has some inputs on that it would be great .
Estimation for the rocket motor performance cannot be exact because exact burning profile or ISP is in secret. Also, my CFD also has limitation in accuracy because of limited computing source.

Now I am currently working for addition of air-breathing propulsion for my Missile-SIM, like ramjet and scramjet.
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Old 01-09-2019, 12:41 PM   #10
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Hi,

Since we are mainly interested into DCS here, it would be great to be able to input DCS missiles parameters.
It would allow us to check various missiles performance without having to set up the mission in mission editor and flying the mission.
This is very time consuming.
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