在战斗机的设计中，在研制过程中尽早对飞机的飞行动态进行评估和分析是非常重要的。一种情况是外部存储释放过程的动态性。在初步设计阶段，可以使用仿真工具来分析战斗机/外挂系统的动力学。本文通过仿真研究了不对称推进中程空对空导弹(AMRAAM)发射过程中喷气式战斗机试验(JF-1 E)的飞行动力学。JF-1 E和AIM 120 AMRAAAM模型采用AAA和导弹Missile Datcom软件建造。利用这些软件，可以获得飞行器的气动稳定性和控制导数，并将其应用于战斗机和外存储器的动态特性建模。利用MATLAB/Simulink软件对动态系统进行建模。利用该软件模拟了歼击机/外挂的集成过程和外挂的发布过程，分析了系统的动态特性。
Generally, a fighter is designed to paralyze the enemies. For this purpose, a fighter usually equipped with weapons or external stores such as missiles, bombs, rockets, etc. In case of external store release to attack enemies, a fighter undergoes a huge disturbance due to the loss of components with a large mass and a considerable aerodynamics contribution. If left unchecked, this process could interfere the fighter’s combat operation. Therefore, the dynamics of a fighter in the external store release process is a case that needs to be analyzed and evaluated in the beginning of the development process of the fighter.
One of the method that can be used to perform the analysis is simulation. Simulation has several advantages compared with flight test method. By using this method, it spent only 40% of the fund compared with the flight test method. It is safer to use simulation due to zero percent accident risk. It also prevent losses due to aircraft damage. Simulation is also a flexibel method as it can be done under various conditions.
One of the tool that can be used in simulation is Computational Fluid Dynamics (CFD). CFD can be used to do a lot of simulation and analysis. By using CFD, the static stability derivatives can be computed and then the stability of the aircraft can be modelled and predicted . It can be used to simulate and analyze the separation characteristics of a missile, either using Cartesian grids or using Grid-Free Euler Solver.
Another tool that can be used in the dynamics simulation and analysis is MATLAB/Simulink software. Compared to CFD, the numerical calculation of MATLAB/Simulink is lighter on computer and takes a relatively short time.
Institut Teknologi Bandung (ITB), that has been involved in the development process of IF-X, a fighter that will be produced by Indonesian government in cooperation with South Korea Government, is developing a simulation model and facility for a fighter. The fighter model being developed is named Jet-Fighter Experiment (JF-1 E). In the previous works, besides modeling of JF-1E, air combat maneuvers simulation has also been done. In the next development, it is important to analyze the dynamic response of the fighter for various external store release scenarios. Therefore, a dynamic system that consist of fighter and external store model is needed to be developed.
The present paper will specifically discuss the simulation of JF-1 E’s dynamics in the asymmetric external storage release process using MATLAB/Simulink software.
The modeling of JF-1 E has been done by using Advanced Aircraft Analysis (AAA) software, so the stability and control derivatives of its aircraft has been obtained, both in longitudinal and lateraldirectional dimension. By using Missile Datcom software, the stability derivatives of AIM 120 AMRAAM has been obtained, too. Both AAA and Missile Datcom are suitable softwares for calculating aerodynamic parameters of an aircraft and a missile at the preliminary design stage. Table 1 shows the stability and control derivatives of JF-1 E as the result of the previous works :