Design And Application Of Flexible Intelligent Skin Thermal Flow Sensor

The measurement of flow is the premise and foundation of realizing the aerodynamic control of aircraft,and it is also the key and difficult point in the research of intelligent skin sensing measurement system.In this paper,the flexible thermal sensor which can be used for the velocity measurement of variant aircraft was studied,and the thermal flow rate sensor was explored from many aspects,such as structure design,theoretical modeling and simulation,process optimization,test system design and wind tunnel application verification.The main research work and contributions of the dissertation are introduced as follows:A multifunctional flexible thermal flow sensor integrated with calorimetric and hot-film was designed.The sensor used the combination of hot-film and calorimetric in the structure layout could eliminate the measurement limitation between the different measuring principles of the thermal flow sensor and expand the sensor measurement range,which realized the complementary advantages between the sensing measurement principle.The thermal characteristic mechanism model and the thermal-flow coupling simulation model of the thermal flow sensor were proposed.Combining with the characteristics of sensor structure,a physical model of sensor thermal characteristics based on thermal micro-sensing unit was established,and the relationship between sensor geometric structure parameters and sensitivity was analyzed.Then the thermal-flow coupling model was also constructed by using finite element software to simulate the sensor,and the reasonable size parameters range of the sensor were determined.The key technology and process parameters of thermal flow rate sensor were optimized.Based on the reasonable selection of sensor structure materials,the key technologies of ultrathin through-hole connection,annealing enhancement and aging enhancement based on e-jet printing in the preparation process of flexible sensor were explored.The magnetron sputtering parameters affecting temperature coefficient of resistance(TCR)Ni in film forming process were also optimized,which can improve the stability,reliability and sensitivity of the thermal flow sensor.A thermal flow sensor test system was built and the sensor was also verified by wind tunnel application.According to the principle of sensor testing,the key hardware circuits of the sensor were designed.A flow calculating algorithm based on three spline interpolation function was proposed,and the sensor parameters were also characterized by the test platform.Besides,a typical plate model was selected for wind tunnel testing,and the feasibility and practicability of the sensor in the flow field measurement were also verified.