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国内用激波风洞做动稳定性导数试验已有几年的历史。这类设备的特点是试验时间短,振动周期数少,采样点子较密。测量仅限于一个方向的姿态角θ。数据分析采用WOBBLE技术中的单自由度模型。这样,由于测量误差,换算方法和数学模型误差等的影响。得到的锥模型动导数散布较大。本文分析的重点是:用单自由度模型分析实际上是6自由度的空间运动,会带来多大误差?这是当前试验工作中十分关心的问题之一。具体分析以下几个因素的影响。(1)真实运动是非平面型,而单自由度是平面运动。(2)真实运动一般是滚转的,往往还呈现变转速,即p_0和(?)均不为零,而单自由度是不滚的。(3)真实运动的轨道呈现弯曲的空间曲线,且是减速运动,这是法向力、阻力和重力作用的结果,而单自由度对应于等速直线运动。
Domestic shock wind tunnel dynamic stability derivative test has been a few years of history. Such equipment is characterized by short test time, a small number of vibration cycles, sampling ideas more dense. Measurement is limited to one direction of the attitude angle θ. The data analysis uses the single degree of freedom model in the WOBBLE technique. In this way, due to measurement error, conversion method and mathematical model error and so on. The obtained derivative of the cone derivative is larger. The main point of this paper is: how to analyze the spatial motion of 6 degrees of freedom in single-degree-of-freedom model and how much error is caused? This is one of the most concerned problems in the current experimental work. Specific analysis of the following factors. (1) True motion is non-planar and single-degree of freedom is planar motion. (2) The real motion is generally rolling, often showing variable speed, that p_0 and (?) Are not zero, and single degree of freedom is not rolling. (3) The orbit of the real motion presents a curved curve of the curve, and is a decelerating motion, which is the result of normal force, resistance and gravity, while the single degree of freedom corresponds to a constant velocity linear motion.