涡环旋转伞系统减速导旋效率研究

Study on decelerating and spinning efficiency of vortex ring parachute system

为了解涡环旋转伞的减速导旋特性,提高旋转伞系统的减速导旋效率,以满足某些载物工作状态对转速、落速的苛刻需求,设计一种由涡环旋转伞和圆形减速伞构成的组合伞系统。制作单伞系统和组合伞系统的试验模型,分别进行伞塔试验。基于伞塔试验的高速摄影和图像处理技术,提取伞物系统的弹道数据点,结合弹道模型,用最小二乘法拟合时间弹道数据,得到单伞系统和组合伞系统的极限速度和阻力特征。基于姿态存储测量法,获得伞物系统的转速变化规律。对单伞系统和组合伞系统的弹道规律及减速导旋效率等数据进行对比分析,提出可有效提高旋转伞系统转速落速比的方法。结果表明:对高速录像进行图像处理可简单快速有效地提取伞物系统的极限速度和阻力特征;单具涡环旋转伞可提供更大扭矩,使载物旋转加速度更大,其导旋效率高;组合伞可提供更大阻力,使载物极限落速更低,其减速效率高;组合伞系统的转速落速比更大,整体性能优于单伞系统。

To understand the decelerating and spinning characteristics of vortex ring parachute,increase the decelerating and spinning efficiency of rotating parachute system,and satisfy the harsh demand of limiting falling speed and rotating speed for some payloads at specific working state,a compound parachute system composed of a circle drag parachute and a vortex ring parachute was designed.The test models of single parachute system and compound parachute system were made out?and then two tower tests were carried out separately.Based on high speed photography of parachute tower test and image processing technology,the trajectory data points of the parachute-payload system were extracted.Combining with the trajectory model,the time and trajectory data was fitted by least square method,the limiting falling speed and the resistance characteristics of the system were obtained.Using attitude memory-measuring technology,the rotating speed changing law of parachute-payload system was gained.The trajectory laws and the decelerating and spinning efficiency of the vortex ring parachute and thecompound parachute system were analyzed contrastively,and then the method to increase theratio of rotating speed and limiting falling speed availably was proposed.The results show that through processing the pictures shot by high-speed camera,the limiting falling characteristics of the parachute-payload system can be extracted quickly and efficiently.The single vortex ring parachute could provide bigger torque so that the rotating accelerating of the payload is higher,which means that the spinning efficiency is better.The compound parachute could bigger resistance so that the limiting falling speed of the payload is lower,which means that the decelerating efficiency is better.The radio of rotating speed and falling speed of compound parachute system is bigger than that of single parachute system,which means that the whole performance of compound parachute system is better.