Computational Study on Thermal Motion Sensors That Can Measure Acceleration and Rotation Simultaneously

Area of Science:

• Multiphysics simulation
• Sensor technology
• Computational fluid dynamics (CFD)

Background:

• Existing physical sensors, like thermal motion sensors, have limitations in simultaneous measurement.
• Conventional thermal accelerometers rely on fundamental conservation laws (mass, momentum, energy).
• Cross-axis sensitivity in sensors relates output signals on perpendicular axes to input physical quantities.

Purpose of the Study:

• To propose and validate a new numerical simulation technique for simultaneous measurement of multiple physical quantities.
• To demonstrate the simultaneous measurement of acceleration and rotation using a modified thermal sensor.
• To investigate the correlation between temperature distribution and applied acceleration/rotational speed.

Main Methods:

• Numerical simulations utilizing commercial software (FLUENT) based on conservation laws.
• Discretization of governing equations for sensor response prediction.
• Parametric studies to optimize sensor-heater distance and evaluate gas medium effects (e.g., CO2).

Main Results:

• A novel method correlating maximum temperature values around a heating source with acceleration and rotational speed is proposed.
• Computational studies successfully demonstrated the principle of simultaneous acceleration and rotation measurement.
• Carbon dioxide (CO2) was identified as the optimal gas medium, enhancing sensor performance due to its physical properties.

Conclusions:

• The proposed numerical simulation technique enables simultaneous measurement of multiple physical quantities.
• The modified thermal sensor, leveraging cross-axis sensitivity, effectively measures acceleration and rotation.
• Gas medium properties significantly influence sensor performance, with CO2 offering superior results.