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Initial Version of Missile-SIM for Performance evaluation - my own

litzj

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https://jaesan-aero.blogspot.com/2018/09/initial-version-of-missile-sim-for.html

I want to get some feed back or useful information related to my simulation

Recently, I have worked some Python code for Missile-Rocket-Projectile Simulation having 2DOF.

Because I could only simulate lift/drag characteristics of the missile body as shown in Fig. 5, my simulation is relatively simple. Full 6DOF simulation work have been developed for Matlab code when the full 6DOF data, inertia, center of gravity, moment coefficient, is available, however, in most cases, it is not available.

Most of my article in the past was relied on estimation of hunch or prediction from common sense, however, I realized better tool for estimation is required. Although, modification of past Matlab code is easier way, study of python code is also enjoyable.

As a future plan, I perform CFD for supersonic reference cases via ANSA + StarCCM while improvement for this code will be done. below CFD figure is example.

After completion, analysis for Missile/SCRAMJET/Cruise Missile is on plan

1. Implemented
- Atmospheric / Gravity condition change via Altitude
- Calculation of Altitude, Speed, Range from Input Trajectory
- Consideration of multi-pulse or stage rocket
- Usage of Aerodynamic data for Mach/AoA

2. Planned or WIP
- Range optimization for missile? - recommendation of paper/report
- 3DoF/6DoF expansion - not planned (precise data for Inertia, CG is not available)
- Good reference case for certain missile shape - recommendation of paper/report
 

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DrRansom

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For trajectories - the mid-course phase is probably going to be a ballistic arc. Right now the trajectories look to be piecewise constants. This is more complicated, basically look for some form of gravity turn?

Note: finding the exact midcourse trajectories of surface to air and air to air missiles is rather hard. There are precious few research papers about midcourse trajectories, compared to the massive number of articles about terminal guidance.
 

litzj

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DrRansom said:
For trajectories - the mid-course phase is probably going to be a ballistic arc. Right now the trajectories look to be piecewise constants. This is more complicated, basically look for some form of gravity turn?

Note: finding the exact midcourse trajectories of surface to air and air to air missiles is rather hard. There are precious few research papers about midcourse trajectories, compared to the massive number of articles about terminal guidance.
Gravity turn requires calculation of pitching moment direction which is not considered yet (but in future plan)

At this stage, I primary consider Air-to-Air or Cruise missile in given course.
 

litzj

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litzj

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Full detail of the Article is here.

https://jaesan-aero.blogspot.com/2018/10/aim-120c-study-using-missile-sim-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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Dragon029

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You might want to also throw in a notional concept of a CUDA+booster, but where the booster is air-breathing (you could perhaps base it off a shortened Meteor propulsion section).
 

litzj

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Dragon029 said:
You might want to also throw in a notional concept of a CUDA+booster, but where the booster is air-breathing (you could perhaps base it off a shortened Meteor propulsion section).
it would be interesting, but I never saw similar concept about this.
 

AeroFranz

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Very interesting. Props to you for all this work! ;)
 
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