【作者】 胡志鹏；

【导师】 刘荣忠；

【作者基本信息】 南京理工大学 ， 火炮、自动武器与弹药工程， 2013， 博士

【摘要】 本文对现有稳态扫描技术进行改进,提出了采用两片小展弦比尾翼作为末敏弹气动机构实现稳态扫描运动的技术方案。该方案利用尾翼产生非对称的气动力形成旋转运动实现稳态扫描。本文采用理论分析、数值计算和试验研究相结合的方法,对双翼末敏弹稳态扫描运动特性、气动特性以及扫描运动稳定性进行了系统的研究,为无伞末敏弹结构设计和气动外形改进提供了理论依据和技术支持。本文的主要研究内容包括以下几个方面：1)双翼末敏弹稳态扫描运动特性研究全面考虑了弹丸质量、空气动力等非对称因素,建立了大攻角状态下双翼末敏弹运动模型。进一步就双翼末敏弹弹体、两片尾翼分别进行受力分析,采用多刚体运动理论,建立了符合实际运动过程的双翼末敏弹大攻角非线性多刚体运动模型。针对双翼末敏弹运动姿态变化大的特点,采用不会出现退化的四元数法描述末敏弹的转动运动。编制了适合计算机求解的程序,获得了双翼末敏弹的运动参数,理论上分析了双翼末敏弹运动特性,为双翼末敏弹物理模型的设计和运动稳定性研究奠定了理论基础。结果表明,多刚体系统模型可以很好地描述双翼末敏弹的稳态扫描运动。2)尾翼结构参数对双翼末敏弹运动特性影响的试验研究依据无伞末敏弹气动外形设计原则,设计了平板尾翼末敏弹、S-C形尾翼末敏弹和S-S形尾翼末敏弹物理模型。进行了高塔投放的自由飞行试验,分析了三种不同尾翼形状末敏弹的运动特性。试验结果表明,无尾翼安装角的平板尾翼末敏弹不具有形成扫描运动的条件,S-C型尾翼末敏弹和S-S型尾翼末敏弹因尾翼弯折角存在能够形成扫描运动。试验得到了尾翼面积对S-C形尾翼和S-S形尾翼末敏弹运动特性影响规律：尾翼面积增加显著提高双翼末敏弹阻力系数,降低了落速,但对转动力矩系数的提升有限。试验研究了尾翼弯折角对S-S形尾翼末敏弹运动特性影响,增加尾翼弯折角在提高末敏弹转动速度的同时也增加了末敏弹运动的不稳定性。自由飞行试验为选择适合稳态扫描运动的末敏弹翼形提供依据。3)尾翼结构对双翼末敏弹气动特性的影响研究基于计算流体力学方法,对自由飞行试验的双翼末敏弹气动外形进行流场计算。获得了平板尾翼、S-C形尾翼和S-S形尾翼末敏弹三种模型的表面压力分布规律和阻力系数、升力系数和转动力矩系数随攻角变化的规律。进一步分析了不同翼展、弦长时S-C形尾翼和S-S形尾翼末敏弹的气动特性。结果表明,增加尾翼面积对增加阻力系数作用明显,对升力系数及转动力矩系数影响较小。通过尾翼弯折角组合对S-S形尾翼末敏弹气动特性影响的研究发现,尾翼弯折角是S-S形尾翼末敏弹转动力矩的主要影响因素。4)无伞末敏弹运动稳定性研究以带有安装角的平板尾翼末敏弹为模型,理论、系统地进行了双翼末敏弹运动稳定性的研究。考虑大攻角运动特征,对双翼末敏弹受力分析并推导了转动运动状态方程,根据奇点理论,分析了末敏弹运动稳定性判据。明确以参数化方式表示的运动稳定区间,阐明各结构参量对双翼末敏弹运动稳定性的影响规律。为末敏弹稳态扫描设计及参数提供了重要的理论支持。更多还原

【Abstract】 This thesis presents a novel scheme of realizing stable scanning technology which uses two pieces of low aspect ratio wings on the basis of analysis of the advantages and disadvantages of the existing stable scanning technology of Parachute Terminal Sensitive Projectile. This method achieves stable scanning motion by using the spin resonance motion caused by asymmetry of the aerodynamic force. Combined with theoretical analysis, numerical and experimental study, the motion characteristics, aerodynamic characteristics and scanning movement stability of the Two-wings Terminal Sensitive Projectile have been studied systematically to supply a theoretical foundation and technical support for the design and improvement of Two-wings Terminal Sensitive Projectile.The main researchs of the thesis include:1) Research on the characteristic of Two-wings Terminal Sensitive Projectile stable scanning motion.Consider the Two-wings Terminal Sensitive Projectile is a system contained three rigid body wich are the projectile and two wings. Anylyzed the aerodynamic force and monent in the condition of high angle of attack and established the nonlinear motion model of the Two-wings Terminal Sensitive Projectile. Considering that the Two-wings Terminal Sensitive Projectile’s attitude changes great during free flight, quaternion method is used to process the motion model of Two-wings Terminal Sensitive Projectile, and standardized equations which are suitable for machine programmingare established, and computer programs of model are developed which give procedures example. Results show that the designed Two-wings Terminal Sensitive Projectile system can achieve stable scanning motion.2) Experimental study on the wing’s structure parameters effect on the stable scanning motion characteristic.Terminal Sensitive Projectile aerodynamic design principles are established on the basis of theoretical study, according to which the Two-wings Terminal Sensitive Projectile physical model is designed and the tower free flight tests are placed. Then the motion characteristics of flat-wing model, S-C wing model and S-S wing model are analyzed. Based on the experimental study, S-C wing and S-S wing Terminal Sensitive Projectile can achieve stable scanning motion while the flat-wing model can’t. Furthermore, the rules of area of wings effect on the motion characteristics were gotten. The drag coefficient increase with the area of the wings increasing and the moment coefficient have a little change with the area of the wings increasing. The experiment alse shows that with the increasing of the area of wings the moment increasing while the stability greatly decreased. According to the free flight experiment, the wing shape selection criteria of Two-wings Terminal Sensitive Projectile which is appropriate for stable scanning is determined.3) The study on the wing’s structure parameters effect on the aerodynamic characteristic Terminal Sensitive Projectile.Flow field and aerodynamic force of Two-wings Terminal Sensitive Projectile are numerically calculated by using Computational Fluid Dynamics method. We obtained the rules of surface pressure distribution and drag coefficient and lift coefficient and torque coefficient changes with angle of attack. Further anylized the aerodynamic characteristics of Two-wings Terminal Sensitive Projectile with different wingspan and chord. Results show that the increase of area of wings has significantly increase the drag coefficient, less about lift coefficient and torque coefficient. Through the study on the aerodynamic characteristics of S-S wing Terminal Sensitive Projectile with diffirent combination of wing angle found that wing angle is the main influencing factor on torque coefficient.4) Study on movement stability of non-parachute Terminal Sensitive Projectile.Base on plat wing Terminal Sensitive Projectile model, in theory systematic study on stability of the Two-wings Terminal Sensitive Projectile scanning motion. Considering the high angle of attack characteristics, anylize the forece and establish perturbation equations of motion. According to Singularity Theory, analysis of Two-wings Terminal Sensitive Projectile motion stability criteria. Clear a parametric representation of the movement stable range, clarifying the structure parameters on the Terminal Sensitive Projectile motion stability effects. The stability analysis of Two-wings Terminal Sensitive Projectile motion provide theoretical support for Two-wings Terminal Sensitive Projectile stable scanning platform design.更多还原