Table of Contents

Aerodynamics Series

2018년 10월 21일 일요일

AIM-120C Study using Missile-SIM : Part 2 - Launch Condition

Previous Work Status

Initial Version of Missile-SIM for Performance evaluation
Aerodynamic Validation of Missile-SIM for Trajectory 
AIM-120C Study using Missile-SIM : Part 1 - Sensitivity

 Next part of PART 1 - Sensitivity, I continued Study for performance of AIM-120C; impact of launch condition is investigated as follows. 

 Part 2 : Launch Condition Analysis / Optimization of AIM-120C
 List of parameters for AIM-120C Trajectory condition: Altitude, Speed, Climb time, Climb angle, Burn-mode change. Additionally, optimization for climb angle/time is done while impact of trajectory optimization and hardware upgrade is configured. 

(1) Launch Altitude

 Kinematic range of the missile is very sensitive to launch altitude; exponential fitting is required. 

(2) Launch Speed

Both Peak speed and Range is linearly proportional to the launch speed. 

(3) Climb Time

Climb time naturally increases cruise altitude of the missile, and getting higher altitude via more climb time increase the kinematic range. 

(4) Climb angle

Steep climb angle leads to high cruise altitude as shown in the result of climb time, indeed, higher climb angle leads to longer kinematic range. 

(5) Dive angle

AIM-120C missile should stay in high altitude to maintain its speed. 

(6) Range Estimation

 Range equation at horizontal trajectory can be obtained in terms of launch altitude and Mach number. We could estimate range change of AIM-120C for launch condition and hardware update (from part 1)

 (7) Trajectory optimization (Range increase)

Larger climb angle and longer time is the best optimization option; detailed result is at below

(8) Burn mode test

Unfortunately, there is no information about "Longer burn time", so extremely long burn time is tested for boost-Sustain mode. Result shows enhancement of usage of the mode. 

(9) Trajectory optimization w/ possible upgrade

Optimized trajectory already extend the range for 140% without huge impact on peak speed. Also minor(?) update of the missile for each component could contribute the range extension. From the result, we could figure out that trajectory and minor update of rocket motor could enhance the missile range significantly. 

(10) Range Estimation for optimized trajectory

Impact of hardware change of missile is changed as trajectory is updated. Because missile is cruising at high altitude with lower drag, sensitivity of missile is increased. 

(11) Conclusion

 In Part 3 and 4, I will represent result for CUDA class w/ booster and Ramjet missile respectively. 

댓글 3개:

  1. I found there is bug for altitude change (ft to m); I will fix the result for altitude change

  2. Hi I like your work
    Am undergraduate student I need the matlab code you made in Ramjet part_3

    1. This code is basically coded by Python, not matlab. And I should ask who are you? and what is usage of this code?