Design And Thermal Fatigue Simulation Analysis Of High-temperature Sensors

Through the condition detection of aero-engine edges,the faults of the blades are detected and troubleshot,which significantly,improves the cost and efficiency of aero-engine testing.Optical fiber tip timing sensors have the advantages of fast response,high precision,and strong resistance to electromagnetic interference,and are widely used in the vibration state monitoring process of aero-engine blades.With the development of aero engines and gas turbine units,their internal working temperature and working pressure are also rising,so the current temperature of the gas inside the casing has risen to 1300 K.However,the existing tip timing sensor can not meet the measurement needs in high-temperature environments,to ensure continuous health monitoring of the blades of the aircraft engine,it is urgent to design a high-temperature fiber tip timing sensor that can work in a high pressure and high-temperature environment of 1300 K.Based on the current research background of online monitoring of aero engine blade vibration and the needs of the existing blade state detection field,a high-temperature optical fiber blade tip timing sensor capable of long-term service in a 1300 K operating environment has been developed in this paper.Using heat transfer theory,flow field analysis theory,thermal stress analysis theory,and fatigue life analysis theory,carried out the cooling structure design,flow field analysis,and thermal stress calculation of the high-temperature fiber tip timing sensor.Proposing the fatigue damage and fatigue life calculation method of high-temperature fiber tip timing sensor based on fatigue analysis software n Code.(1)Designed the structure of the high-temperature optical fiber tip timing sensor and established a three-dimensional model.Then simulating and analyzing the temperature field,pressure field,and streamline diagram of the high-temperature sensor,cooling flow field,and high-temperature gas flow field.Finally,the reliability of the high-temperature fiber inter-leaf timing sensor is verified by thermal fluid-structure interaction calculation.(2)The temperature field and pressure field of the high-temperature sensor calculated by the thermal fluid-structure interaction are loaded into the sensor as temperature load and pressure load for thermal stress-strain analysis.The analysis determines the area of stress concentration of the sensor and the area most prone to fatigue damage and failure,which provides a data basis for the subsequent life calculation of the high-temperature sensor.(3)The fatigue life of the high-temperature fiber tip timing sensor was analyzed based on the low-cycle fatigue correlation theory.We are using n Code fatigue analysis to calculate the fatigue life of the sensor.The dangerous position of the fatigue damage of the high-temperature optical fiber sensor in the high-temperature and high-pressure environment and the cumulative damage degree is obtained through calculation.(4)We have built a high-temperature sensor testing platform and conducted temperature resistance verification experiments on hightemperature fiber optic tip timing sensors.The sensors were tested under simulated high-temperature environments,and indicated the sensor meets the measurement requirements of high-temperature environments..