Luo Xuwen, Wang Haidong
Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China.
Materials (Basel). 2022 Aug 5;15(15):5385. doi: 10.3390/ma15155385.
The thermal measurement sensor applied to hypersonic vehicles requires characteristic size in the order of micrometers and characteristic time in the order of microseconds. The measurement criteria of localized detection, high temporal-spatial precision, and long-term stability cannot all be reached by current thermal measuring techniques. This work presents a temperature sensor with excellent temporal-spatial resolution that can measure both in-plane and out-of-plane heat flow. The sensor was made of thin platinum nano-film and an aluminum nitride ceramic sheet. The sensor was calibrated using a thermostatic vacuum chamber and used for in-plane and out-of-plane heat flow measurements. The temperature measurement accuracy of the sensor was estimated to be 0.01 K. The sensor's resolution for measuring heat flow density is more than 500 W/m and its measurement uncertainty is roughly 3%. To ensure the structural stability of the device, the aluminum nitride ceramic sheet was chosen as the substrate of the thermal sensing unit, and the response time became longer due to the high thermal conductivity of aluminum nitride. The suspension platinum nano-film sensor can reach a sub-microsecond response time according to the theoretical derivation. Experimental results of pneumatic thermal effects of high-temperature flames using the sensor prove that the designed sensor has good sensitivity and accuracy.
应用于高超音速飞行器的热测量传感器需要微米级的特征尺寸和微秒级的特征时间。当前的热测量技术无法同时满足局部检测、高时空精度和长期稳定性的测量标准。这项工作提出了一种具有出色时空分辨率的温度传感器，它可以测量平面内和平面外的热流。该传感器由薄铂纳米膜和氮化铝陶瓷片制成。该传感器使用恒温真空室进行校准，并用于平面内和平面外的热流测量。估计该传感器的温度测量精度为0.01K。该传感器测量热流密度的分辨率超过500W/m，其测量不确定度约为3%。为确保器件的结构稳定性，选择氮化铝陶瓷片作为热传感单元的基板，由于氮化铝的高导热性，响应时间变长。根据理论推导，悬浮铂纳米膜传感器可以达到亚微秒级的响应时间。使用该传感器对高温火焰气动热效应的实验结果证明，所设计的传感器具有良好的灵敏度和准确性。
