Design Of Ultrasonic Guided Wave Resonance Temperature Sensor And System Based On Mo-Re Alloy

With the development of key equipment such as hypervelocity aircraft and advanced engines,some key components of equipment are exposed to ultra-high temperature environment caused by combustion or high-speed friction.Long-term ultra-high temperature will damage parts or even cause accidents.Therefore,it is particularly important to measure the temperature in such a long time ultra-high temperature environment.In addition to high temperature and vibration resistance,the temperature sensor should also have the reliability and stability to work at high temperature for a long time.At present,there is no effective measurement method for continuous temperature measurement in ultra-high temperature environment above 1600? in China.For the temperature measurement in such extreme environment,thermocouple temperature measurement method and radiation temperature measurement method are two commonly used methods.The upper limit of thermocouple temperature cannot meet the requirements due to the limitation of response speed and thermocouple material.The radiation source temperature measurement method is susceptible to environmental hazards in the whole process of temperature measurement,and the deviation is relatively large.Aiming at the shortcomings of the above temperature measurement methods,this paper presents a new method for resonant temperature measurement using ultrasonic guided waves.Ultrasonic guided wave resonance temperature measurement is a kind of contact temperature measurement method,the method has the characteristics of non-contact,no influence on the measured object,and can detect the measured object in real time,and has a fast response speed.According to the basic principle of ultrasonic guided wave method,the key dimension parameters of Mo-Re alloy guided wave resonant temperature sensor are determined by calculation method.The hardware is based on FPGA with resonant frequency automatic tracking circuit to realize ultrasonic transmission,resonant frequency measurement,resonant echo signal acquisition and USB data transmission.The software system develops LabVIEW PC to realize parameter sending,resonant echo data display,collection and storage.Based on the ultrasonic guided wave temperature sensor,an experimental platform was built to measure the temperature.Through calibration experiments,the temperature-resonant frequency function of Mo-Re alloy sensor was obtained at 20? 1800?.The results show that the repeatability error of the Mo-Re alloy temperature sensor is 3.59%.The resolution is 0.1%.The sensitivity is 0.04 k Hz/?.