摘要
偏转头部控制是一种新概念快速响应的控制方式。弹头部相对于弹轴进行局部偏转,并且在弹头的迎风面和背风面形成压力差从而产生空气控制力,在弹药系统里,这是一个高效并具有良好应用前景的控制方式。基于智能材料和结构的弹箭头部智能变形驱动机构可以使弹箭获得额外的控制力和控制力矩,改变弹丸在飞行过程中的空气动力特性,在弹箭飞行过程中会产生附加的平衡角、侧滑角,进而产生机动过载,控制飞行姿态和飞行弹道,并在最后时限提高弹丸的射击精确度。为了研究自适应控制弹箭的特性,利用流体力学软件对尾翼稳定的火箭弹进行了数值模拟。获得不同头部偏角、不同马赫数和不同攻角情况下的弹箭空气动力学特性。结果表明,偏转头部控制对弹箭的头部具有较大的影响,并且引起流场的不对称性。弹头部迎风面和背风面的压力差为弹箭提供较大的升力。最后,做弹道试验验证了仿真的研究结果。研究结果可以为自适应弹箭的设计及优化提供理论基础,并为智能弹药的研究提供新思路和新方法。
Nose deflection control is a new concept of fast response control model.The partial nose of projectile deflects a certain angle relative to the axis of projectile body and then pressure difference emerges on the windward and leeward sides of warhead.Consequently,aerodynamic control force is generated.This control way has high control efficiency and very good application prospects in the ammunition system.Nose deflection actuator based on smart material and structure enables projectile body morphing to obtain additional aerodynamic force and moment,changes the aerodynamic characteristics in the projectile flight process,produces the corresponding balance angle and sideslip angle resulting in motor overload,adjusts flight moving posture to control the ballistics,finally changes shooting range and improves firing accuracy.In order to study characteristics of self-adaptive control projectile,numerical simulations are conducted by using fluid dynamics software ANSYS FLUENT for stabilized rocket projectile.The aerodynamic characteristics at different nose delectation angles,different Mach numbers and different angles of attack are obtained and compared.The results show that the nose deflection control has great influence on the head of rocket projectile,and it causes the asymmetry of the flow field structure and the increase of pressure differences of the warhead on the windward and leeward surface,which results in a larger lift.Finally,ballistics experiments are done for verification.The results can offer theoretical basis for self-adaptive rocket projectile design and optimization and also provide new ideas and methods for field smart ammunition research.
关键词
火箭弹
智能变形技术
头部偏转
弹道特性
rocket projectile
intelligent morphing technology
nose deflection
ballistics characteristics