恒温型热线风速测量系统动态特性分析及试验验证  

Dynamic characteristic analysis and experiment verification of hotwire wind velocity measurement system with constant temperature control loop

作　　者：韦青燕[1] 张天宏[1] 沈杰[1] 金晖[1] 

机构地区：[1]南京航空航天大学能源与动力学院江苏省航空动力系统重点实验室,南京210016

出　　处：《仪器仪表学报》2015年第10期2265-2272,共8页Chinese Journal of Scientific Instrument

基　　金：国家自然科学基金(51176075)项目资助

摘　　要：为测量不同工况下流场的脉动流速,恒温型热线风速测量系统在满足稳定性要求的同时,必须具备宽频带的动态特性。分别对热线探头工作过热比、放大器增益、惠斯通桥臂电阻、流场稳定流速、补偿电感和偏置电压等参量对热线测量系统动态特性的影响效果进行了仿真分析,结果表明:增大热线探头工作过热比、放大器增益和流场稳定流速及减小桥臂电阻均能提高系统的频响;补偿电感与热线探头连接电缆电感及电路寄生电感匹配时,系统频响最佳;在上述参量配置不当时,系统频响降低,系统振荡加剧甚至不能正常工作,而提高偏置电压能消除振荡并使系统恢复稳定,同时获得平稳的动态频响。因此,提出了基于偏置电压的动态特性调节方法。方波试验结果表明,基于偏置电压的频响调节方法能使系统在不同的脉动流速测量中均能获得较为平坦的频响,且调节过程简便。In order to measure the fluctuation velocity of the flow field in different operation conditions,the hotwire wind velocity measurement system with constant temperature control loop（ CTCL） must possess broad frequency band dynamic characteristic in addition to meet the stability requirement. In this paper,the effects of hotwire probe operation overheat ratio,amplifier gain,Wheatstone bridge arm resistances,flow field steady flow velocity,compensation inductance,offset voltage,and etc. on the dynamic characteristic of the hotwire wind velocity measurement system are analyzed in simulation. The simulation results show that the frequency response of the system is improved when increasing the hotwire probe operation overheat ratio,amplifier gain and flow field steady flow velocity,as well as decreasing the bridge arm resistances. The frequency response of the system is optimal when the compensation inductance and the connection cable inductance of the hotwire probe as well as the circuit parasitic inductance are matched. When the above parameters are not configured properly,the frequency response of the hotwire wind velocity measurement system will decrease,the system will oscillate severely,even can not work normally; however,increasing the offset voltage can eliminate the oscillation and make the system restore stable operation and obtain steady dynamic characteristics. So,a dynamic characteristic tuning method for the hotwire wind velocity measurement system with CTCL based on offset voltage is proposed. The square wave experiment results show that the frequency response tuning method based on offset voltage can make the system obtain relatively flat frequency response in different fluctuation velocity measurements,and the tuning process is simple and convenient.

关 键 词：热线风速仪 恒温型控制回路 动态特性 方波试验 偏置电压 

分 类 号：TH815[机械工程—仪器科学与技术]