高速风洞试验模型姿态角的视频测量及不确定度研究

高速风洞测力试验中,阻力系数精度σc x的先进指标为0.0001,按误差分配原理,要求试验模型迎角的测量精度σα≤0.01°。为此,研究风洞试验中模型姿态角视频测量及其不确定度,给出其系统误差的补偿方法。实测数据（马赫数为1.5、2.0、3.0和4.0）表明：在2m暂冲式超声速风洞试验中,各阶梯迎角测量数据的标准差（含风洞气流脉动致模型姿态角振动产生的误差）在0.0018°和0.0094°之间,迎角实测估计值的标准不确定度≤0.003°,由此可知,姿态角视频测量系统的σα≤0.0094°。本方法既不破坏模型的外形,又不改变模型的刚度与强度,具有实用价值。

Videogrammetry for model＇s attitude and its uncertainty in high-speed wind tunnel testing

The advanced precision of drag coefficient is 0. 0001 for the high speed wind tunnel test of measuring forces, and the model＇s attack angle precision is ≤0.01° following the errors distribution. The videogrammetric uncertainty of model＇s attitude is therefore investigated. And a compensation method of its systematic error is also presented in this paper. The four engineer- ing videogrammetric experiments of attack angle in 2 meter supersonic wind tunnel have demon- strated that the standard deviation of the measured data on each step ranges from 0. 0018° to 0. 0094°（including the errors of attack angle caused by the flow pulsation of 2 meter supersonic wind tunnel）, and the standard uncertainty of evaluated attack angle is ≤0. 003°. As a result, the angle measuring precision of this videogrammetric system is 0. 0094° or less. The compensa- tion method neither destroys aerodynamic shape, nor changes the model＇s rigidity and intensity, so it is useful and effective.