小幅值气动摩擦力测量与干扰补偿研究

Research on measurement and interference compensation of small amplitude aerodynamic friction force

飞行器表面摩擦力的测量是一项重要的工程问题,测量通常使用一定缩比的飞行器模型在风洞实验中进行,测量时总压远高于表面摩擦力,易对摩擦力测量产生干扰,增加测量难度。针对这一问题,提出了一种小感应面的小力测量装置,在实现毫牛级表面摩擦力测量的同时可消除法向空气压力的干扰。设计测量装置整体结构,对关键件尺寸进行参数化设计,得到最优尺寸后进行标定实验,结果显示非线性误差0.882%,重复性误差1.918%。将干扰实验中的测量数据代入修正模型,所测数据经修正后误差由406.3%下降为1.4%。实验结果表明:该测量装置性能良好,能够消除压力干扰,可用于实际测量。

The measurement of surface friction of aircraft is an important engineering problem.The friction measurement is usually carried out in wind tunnel experiments using a certain scaled aircraft model.During the measurement,the total pressure is much higher than the surface friction,which easily interferes with the measurement of friction and increases the difficulty of measurement.Aiming at this problem,a small force measuring device with a small sensing surface is proposed.The device can eliminate the interference of air pressure while realizing the measurement of milli-Newton surface friction.The structure of the measuring device is designed and Parametric design of the size of key parts is carried out.A calibration experiment is performed on the measuring device.The results show that the non-linear error is 0.882%and the repeatability error is 1.918%.Put the measurement data in the interference experiment into the correction model,and the error of the measured data is reduced from 406.3%to 1.4%after correction.Experimental results show that the measurement device has good performance,can eliminate pressure interference,and can be used for actual measurement.