慢周期性流动中毕托管和热线测速的对比

Comparison between Pitot Tube and Hot-wire Anemometer in Slow Periodic Flows

本文采用微机控制调速系统控制低速风洞,在风洞内获得流速按周期性变化的气流.用毕托管和热线风速仪同时测量风洞内按周期性变化的气流速度.毕托管所测结果与热线测得结果相比有较大的相位滞后和振幅衰减.本文分析了毕托管的动态响应特性,采用一阶传递函数对毕托管测速系统的动态特性进行描述,并确定了测速系统的惯性时间和纯滞后时间.

A micro computer controlled low speed wind tunnel is used to produce periodic flows.A pitot tube and a hot-wire anemometer are used to measure periodically varying velocity of flows.The results measured with Pitot tube shows pretty big phase lag and smaller amplitude while compared with that measured with hot-wire.The dynamic re- sponse of pitot tube is analysed,and a first order transfer function is used to describe the dynamic characteristics of Pitot tube.The inertia time and time lag of the transfer function are determined.