风洞试验中测压管路信号畸变及修正研究

采用分布摩擦模型和试验方法分析了简单测压管路系统的信号畸变,分析了数学方法和机械方法修正测试信号的优缺点;讨论了不同参数对管路系统传递函数的影响,同时说明了试验中常见管路连接、弯折、挤压对管路系统的影响,提出了合理利用管路共振效应提高测试数据信噪比的思想,并基于此提出了管路系统的选择及定量的评价准则。结果表明：采用分布摩擦模型理论修正测压管路系统脉动畸变信号是可行的;管路等内径连接、轻度弯折、轻度挤压不会对管路的传递函数造成影响;通过笔者提出的定量评价标准可以高效的选取合理的管路长度。

Study on correction and distortion effects caused by tubing systems of pressure measurements in wind tunnel

The distortion effects caused by simple tubing systems of pressure measurements are analyzed via distributed friction model and fluctuating pressure testing.Advantages and disadvantages of mathematical and mechanical methods for correcting the distorted fluctuating pressures are described.The effects of different parameters and tube connecting,bending,extruding on transfer function of tubing system are discussed.The new idea of acoustic resonances utilization,which improve signal to noise ratio,is proposed.According to acoustic resonances utilization,the tubing systems selection and quantitative evaluation criteria are provided in this paper.The results show that distributed friction model is a feasible approach for correcting the distorted fluctuating pressures.The effect of tube connecting in the same internal diameter,slight bending and extruding on transfer function of tubing system can be neglected.According to the quantitative evaluation criteria proposed in this paper,the tubing system is selected effectively.