A High Temporal-Spatial Resolution Temperature Sensor for Simultaneous Measurement of Anisotropic Heat Flow

Area of Science:

• Materials Science and Engineering
• Aerospace Engineering
• Thermal Physics

Background:

• Hypersonic vehicles demand thermal sensors with micrometer size and microsecond response times.
• Existing thermal measurement techniques struggle to meet criteria for localized detection, high temporal-spatial precision, and long-term stability simultaneously.
• Need for advanced sensors capable of measuring both in-plane and out-of-plane heat flow in extreme environments.

Purpose of the Study:

• To develop and present a novel temperature sensor with superior temporal-spatial resolution for hypersonic applications.
• To enable accurate measurement of both in-plane and out-of-plane heat flow.
• To address the limitations of current thermal measurement technologies in high-speed flight.

Main Methods:

• Fabrication of a sensor using thin platinum nano-film on an aluminum nitride ceramic sheet.
• Calibration of the sensor in a thermostatic vacuum chamber.
• Experimental validation using pneumatic thermal effects of high-temperature flames.

Main Results:

• Achieved temperature measurement accuracy of 0.01 K.
• Demonstrated heat flow density resolution exceeding 500 W/m² with approximately 3% measurement uncertainty.
• Theoretical derivation suggests sub-microsecond response time for a suspended platinum nano-film configuration.

Conclusions:

• The designed sensor effectively measures in-plane and out-of-plane heat flow with high accuracy and sensitivity.
• The platinum nano-film and aluminum nitride substrate provide a robust platform for thermal sensing.
• The sensor shows promise for advanced thermal management and diagnostics in hypersonic vehicles.