【作者】 谢长强；

【导师】 唐硕；

【作者基本信息】 西北工业大学 ， 飞行器设计， 2004， 硕士

【摘要】 从载机上发射导弹、投掷炸弹或抛弃副油箱时，外挂物处于载机复杂干扰流场中。此时往往出现不正常分离，有时会导致外挂物与载机发生碰撞，严重危及载机和飞行人员安全的重大事故。此外，为了有效击中目标，需要掌握投放初始阶段外挂物姿态和运动轨迹数据。因此，研究机载发射过程中的弹机气动干扰力，考虑其对导弹发射后的弹道仿真初始参数的影响十分必要。 在投放／发射分离过程中，外挂物处于载机的近流场中，状态和姿态角的变化可能很大。由于非均匀流场的气动力干扰作用，其气动力与外挂物单独飞行时有较大的不同，获取分离过程中的气动力数据是解决这一问题的关键和难点。 随着CFD计算理论和方法的发展，外挂物的理论计算方法近年来有了很大的发展。与此相映，动态网格计算技术是最近两年计算流体动力学最新发展成熟的重大成果，并且在先进的CFD计算软件中得到了实际的应用，开始为计算飞机投弹之类复杂相对运动造成的时变流场等领域提供了实际可行的工程方法。 本文的主要工作是为对空载发射导弹提供发射初始弹道数据，重点和难点在于机—弹气动干扰力的数值计算。本文具体做了以下工作： 1、借助商业软件进行了模型载机和导弹的CAD三维实体建模，建立了载机和外挂导弹的真实数据三维实体模型； 2、使用商业软件采用非结构网格生成方法及分区网格技术建立了机弹干扰全流场计算网格； 3、利用飞行力学的有关原理编制了导弹离机过程的六自由度动力学及运动学程序； 4、运用商业CFD软件和计算流体动力学方法以及动态网格计算技术求解了机弹干扰动态三维N-S方程，计算出了机-弹干扰流场特性及气动力数据： 5、在以上工作的基础上最终获得了某型导弹离机过程的六自由度运动参数及导弹离机弹道，并进行了仿真结果分析。总的来说，本文的研究证明了气动干扰力特别是载机下洗流场对外挂物发射分离过程有强烈的影响，实际工程中不容忽视，同时本文也表明了CFD计算方法及动态网格技术在机弹干扰复杂流场计算、分离弹道研究的实际可行性和先进性，为今后某型导弹研发和同类问题的进一步研究提供了很好的基础。更多还原

【Abstract】 The investigation of the distribution of aerodynamic forces on the external stores and their neighboring aircraft surfaces during the transient process of the separation of the external store from an aircraft is an urgent need because aerodynamic interactions can cause the released store to impact upon, and possibly damage, the aircraft. The development of CFD(Computational Flow Dynamics) numerical simulation presents a common and powerful solution for the class of problems and will therefore be of considerable benefit in store design with the potential of reducing experimental and flight testing costs.At the same time, the appearance of the dynamic mesh calculation technology supplies us a method that can be used to model flows where the shape of the domain is changing with time due to motion on the domain boundaries.This paper provides a powerful method for the compatibility design of aircraft with external store, a missile, by calculating fast, conveniently and effectively the relative trajectory and relative attitude of the store with respect to aircraft during the separation process. The work of this paper include:1. The 3-D solid entities of the external store, a missile, and the aircraft are modeled with a commercial CAD software.2. The unstructured meshes of the global flowfield are made.3. The program to solve the six-freedom-of-degree dynamics equation and the kinematics equation of the missile are worked out.4. The method of using the commercial CFD engineering software FLUENT to integrate the dynamic mesh calculation technology with the CFD numerical simulation also is described. To use the dynamic mesh model, it is necessary to provide a starting volume mesh and the description of the motion of any moving zones in the model. This paper describes the motion using a C program, a user-defined function (UDF), to calculate the linear and angular velocities from the force balance on the store.The analysis of the results from the numerical simulation shows fairly good effect and it concludes the method can be effectively used to solve the different problems of the similar fields.更多还原