Design and performance evaluation of a novel thin-film heat flux sensor

Thin-film heat flux sensor is suitable for the harsh environment in aerospace application. To further improve the accuracy of testing and to realize the measurement in two directions, this work proposes a new design of the thin-film heat flux sensor. Based on the numerical simulation method, this work investigates the influence of geometric parameters, physical property and working conditions on the sensor test error, and analyzes the testing performances under steady and transient states. Results indicate that the sensor test error is mainly related to the thermal resistance ratio of the sensor in the measurement system. The accuracy of the thin-film heat flux sensor increases with the increase of sensor size or local total thermal resistance. Besides, the newly designed sensor has satisfying steady and transient characteristics, including the small time constant, fast response, and good linear relationship between the measured temperature difference and the surface heat flux.