| In the course of aviation flight,it may be in the rain and fog environment,or the flight under the condition of high Mach number in the high altitude needs to cool the intake air by spraying water,both of which have the presence of liquid droplets.If a common method is used to measure the gas phase temperature under two-phase conditions,the water droplets will adhere to the surface of the temperature probe or evaporate strongly locally,thus affecting the gas phase temperature and making the measurement result lower.In order to reduce the error of the two-phase total temperature measurement,the two-phase total temperature sensor is numerically studied and optimized.In this paper,Creo modeling software was used to establish the physical model and fluid domain model of the sensor,and Ansys CFX was used to conduct numerical simulation of heat transfer in fluid domain and solid domain.Heat transfer between the unmeasured fluid domain,fluid domain and probe,fluid domain and stagnation total temperature sensor,and fluid domain and separation total temperature sensor were calculated.The temperature measurement performance of different sensors under different inlet and drop conditions was studied.The results show that the stagnation effect of the internal fluid of the stagnation sensor is the best,so the precision of the stagnation sensor is the highest under the single-phase condition.Under the two-phase condition,the temperature measurement effect of the total temperature sensor is improved significantly.The more water drop content in the incoming flow,the smaller the diameter of the water drop,and the smaller the error of the separation total temperature sensor compared with other sensors.In order to further improve the measurement accuracy of the sensor,the flow field inside the sensor is taken out as the research object.Since the distance from the sensor inlet to the probe is small compared with the external field,the heat transfer between liquid phase and gas at this distance can be ignored,and the total temperature at the sensor inlet is taken as the real total temperature measured.The probe spacing at the sensor inlet,the area ratio between the inlet and two outlets,separation Angle,probe size and other structural parameters were changed to observe the influence of different structures on temperature measurement results.The optimal sensor structure is obtained by combining the above factors.In order to solve this problem,the number of tests was reduced by orthogonal test,and the order of influence of each parameter of water drop on the temperature measurement results was obtained.Then,through quadratic regression analysis,the correction function of measured temperature and real total temperature is obtained.The measurement results were further modified by this function,and the results showed that the corrected temperature was significantly increased under the conditions of small water droplets and large water content,and the error between the corrected temperature and the real total temperature was significantly reduced. |
