再入弹头小不对称俯仰气动特性测量技术研究

摘要

To accurately measure the micro-asymmetric pitching-aerodynamics of re-entry body remains a challenge for wind tunnel tests.An articulated free-oscillation system based on ball bearings is introduced to measure the dynamic stability derivatives and the static moment simultaneously.The ball bearings provide the degree of freedom in the pitching channel and pro-tect the test model from rupture when elastic beams are fractured because of fatigue.The oscilla-tion frequency and signal quality of the model can be regulated by optimizing the structural di-mension of the detachable elastic beam.The pitching free-oscillation test conducted in Φ500 hy-personic wind tunnel,where the pitching moment reaches the order of 10-6 ,demonstrates the ac-curacy and reliability of this system.%再入弹头小不对称俯仰力矩的精确测量一直是风洞试验领域的一个难题。设计了轴承铰接式自由振动系统，以同时测量模型的动稳定性导数和静力矩系数。滚动轴承提供系统在俯仰通道的自由度，同时在弹性梁断裂时保护模型不受破坏；可拆卸弹性梁可根据试验要求更改结构尺寸，调整系统振动频率及应变片输出信号的质量。利用本系统在Φ500mm 高超声速风洞进行了模型风洞试验，试验结果重复性及试验稳定性好，静态力矩系数测量结果达到10-6量级，证明了系统的精确性与可靠性。