Initial Version of Missile-SIM for Performance evaluation
Aerodynamic Validation of Missile-SIM for Trajectory
AIM-120C Study using Missile-SIM : Part 1 - Sensitivity
AIM-120C Study using Missile-SIM : Part 2 - Launch Condition
AIM-120C Study using Missile-SIM : Part 2 - Launch Condition - revision
Patch note of Missile-SIM : Guidance Algorithm is added w/ Real-Time plot
W.I.P status of Missile-SIM : Addition of Air-propulsion part 1
W.I.P status of Missile-SIM : Addition of Air-propulsion part 2
AIM-120C Study using Missile-SIM : Part 3 - CUDA / LREW / METEOR types. 1 : Baseline Comparison
6. Sensitivity of Generic CUDA / AIM-120C / CUDA+Booster / Ramjet(Meteor)
After comparison of baseline generic model of the 4 missiles, I conducted sensitivity analysis for the hardware change of the missile, weight of the propulsion fuel, burn time of the fuel, ISP value, and drag.
As described in the previous AIM-120C analysis (links in the upper part)
** Heat value % of the fuel is changed for Ramjet because ISP of the missile is not a fixed variable
1) Weight of the fuel
(1) CUDA
2) Burn time of the motor
(1) CUDA
3) ISP value
(1) CUDA
4) Drag
(1) CUDA
5) Summary
(1) Propulsion Weight
Impact of propulsion weight for the 4 missiles are shown.
Smallest and draggy CUDA missile is sensitive among the three solid-fuel missiles. Definitely CUDA has the smallest launch weight and it means small change of the fuel could make huge impact. Meanwhile, CUDA+Booster has the smallest sensitivity because it has the largest portion of the fuel due to its additional stage.
Interestingly, Meteor is much more sensitive than the others because the ISP and range of the missile is great and its impact is also significant.
For their speed, CUDA and its booster version is sensitive because their peak speed is determined at CUDA stage. AIM-120C and Meteor has similar sensitive value for their peak speed. This is mainly caused by the weight of the CUDA is half of the AIM-120 Class.
(2) Burn Time
Impact of burn-time for the 4 missiles are shown.
Sensitivity due to the burn time for the range is roughly similar to the four missiles. Basically longer burn time provides longer range at the same altitude because it avoid energy consumption at the much draggy higher Mach number.
However, it means that longer burn time scarifies its peak speed.
Interestingly, CUDA+Booster is three-times higher sensitivity for its peak speed because this type has much higher peak speed than the others. So, loss of peak speed seems larger.
(3) ISP
Impact of ISP for the 4 missiles are shown.
Because ramjet has heat value for the fuel rather than ISP, it has different unit of sensitivity. Indeed, it is difficult to direct comparison. (1s of ISP is about less than 0.5% of 260s original value)
Among the three solid-fuel missiles, impact of ISP change is significant for the CUDA+Booster.
ISP is the most honest parameter for the missile performance and longer missiles are naturally more affected by the ISP change. (for both range and speed)
(4) Drag
Impact of Drag for the 4 missiles are shown.
Most dreaded enemy of the aerodynamic men, drag only makes negative impact on the missile performance.
Impact of the drag is directly proportional to its range as shown in the range chart. However, for their speed, impact of the drag is little bit different. Peak speed of the CUDA and its boosted version is determined at the draggy CUDA status, indeed impact of the drag is larger than that of AIM-120C.
Meteor having longest range among candidate naturally degraded significantly due to the increase of the drag. Also, its peak speed is reached at the end of the long-burn-time and degradation of the peak speed is also larger than the solid-fuels.
** Model of these missiles are 'generic'-ally made by myself, and precision of the simulation is speculation level; uncertainty of the model is caused by rough CFD mesh, CFD precision, imagined rocket model, atmospheric approximation and more.
************** At Part 3
After this Part 2, I will review some possibilities related to the enhancement of the booster and AIM-120C with trajectory optimization, sometimes called AIM-120D.
As you could see impact of trajectory and hardware through my contents, range of these candidates change significantly due to the slight change of hardware and trajectory optimization.
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