基于CFD/RBD耦合模型的非对称翼双旋弹丸修正机理研究

The two dimensional trajectory correction projectiles (TCP), whose fuzes are replaced by the precision guidance kits, are a kind of intelligent munitions characterized by low-cost and high accuracy. Therefore it is the main trend for army to convert numerous conventional shells to TCPs. However, the traditional approach, which tends to analyze the aerodynamics and flight independently, could not be utilized to predict the dynamic response of spin-stabilized projectile accurately due to the strong coupling contributed by the gyro effect. As the demand for the intelligence of spin-stabilized projectiles, our project will focus on the mechanism of course correction of spin-stabilized projectile and the coupled computational technology between CFD and RBD will be proposed. Specifically, the aerodynamic parameters and the projectile’s attitude will interchange via coupled interfaces. Therefore, results of dynamic response to correction from every time step will be more accurate for the real-time parameters. In terms of precession and aerodynamic derivatives, the mechanism of correction of spin-stabilized projectile will be expressed by the relationship between control forces, the yaw of repose and the swerve trajectory. In addition, the criterion of stabilization and a control strategy suited for spin-stabilized projectile will be put forward.Overall, the reasults of analysis are the premise of the application of two-dimensional trajectory correction.

二维弹道修正弹是一种通过在传统弹丸头部安装二维弹道修正组件，从而提高命中精度的低成本精确打击弹药，是弹药智能化的主要方向。由于陀螺效应使旋转稳定弹丸对横向修正力的响应具有强耦合的特点，传统的分析方法将空气动力和飞行模拟独立地进行分析，结果不具有实时性，更不能反映弹丸对修正力的动态响应特性。本课题研究旋转稳定二维弹道修正弹的修正机理，应用计算流体力学和刚体动力学（CFD/RBD）耦合计算的方法，通过耦合面进行空气动力参数和六自由度飞行姿态参数的双向传递，使得在每个时间步内的动力学参数都具有较高的实时性和精度，准确获得弹丸攻角对修正力的动态响应特性。从进动理论和气动导数角度对旋转稳定弹丸的修正机理进行分析，建立修正力和力矩、动力平衡角以及弹丸轨迹之间的关系，研究弹丸的非线性进动和飞行稳定条件。研究结果可为旋转弹丸二维弹道修正技术走向工程化提供技术支持。

二维弹道修正弹是一种通过在传统弹丸头部安装二维弹道修正组件，从而提高命中精度的低成本精确打击弹药，是弹药智能化的主要方向。围绕旋转稳定非对称翼双旋弹丸亟需解决的基础研究问题，得到了适合于高速旋转体的CFD/RBD耦合计算方法，分析已知弹丸运动状态参数对网格运动预测的效果，探寻高效的耦合面网格处理手段及参数传递方法，在OpenFOAM开源代码库中实现该预测校正方法。建立了旋转稳定弹丸自由飞行耦合计算模型，完成空气动力和陀螺力矩对弹丸“二圆运动”的动态模拟，分析了起始扰动和周期力对攻角振动的影响，揭示动力平衡角对侧向力(矩)的动态响应规律，并由此解释弹道修正弹的横向修正机理。建立了非对称翼双旋弹丸在降弧段的流构耦合模型，研究鸭舵姿态对弹丸运动轨迹的影响规律，分析修正力对弹轴的进动与章动的影响，从弹轴相位变化角度，分析攻角对激励的动态响应性能，探寻可靠稳定的控制策略。研究成果为二维弹道修正弹的气动布局、总体设计和弹道控制方法提供一定的技术支撑，适用于将大中口径炮弹、高旋火箭弹等常规弹药改造成二维弹道修正弹，以及低的成本实现常规弹药的精确化， 为我国的常规弹药向精确化、制导化方向发展提供帮助。