High-Speed and High-Temperature Calorimetric Solid-State Thermal Mass Flow Sensor for Aerospace Application: A...

Area of Science:

• Aerospace Engineering
• Sensor Technology
• Thermodynamics

Background:

• Pitot tubes in aircraft Air Data Systems (ADS) are vulnerable to ice accretion, leading to system failure and loss of critical flight protections.
• Existing thermal mass flow sensors (TMFS) require optimization for high-speed, high-temperature environments.
• Enhancing TMFS reliability is crucial for maintaining aircraft safety.

Purpose of the Study:

• To numerically assess the sensitivity of a high-speed, high-temperature calorimetric solid-state TMFS.
• To investigate the impact of heater-sensor distance and thermal barriers on TMFS performance.
• To improve the reliability of aircraft ADS against environmental hazards like icing.

Main Methods:

• Numerical assessment of a calorimetric solid-state TMFS operating at 573.15 K (300 °C) and measuring airspeeds up to 265 m/s.
• Parametric study on the effect of varying the distance between the heater and thermal sensors.
• Evaluation of the performance enhancement achieved by incorporating a Parylene-N thermal barrier.

Main Results:

• Increasing the heater-sensor distance from 0.1 mm to 0.6 mm improved temperature sensitivity by up to 80% and airspeed sensitivity by up to 100%.
• The addition of a Parylene-N thermal barrier resulted in a nearly 6-fold improvement in sensitivity for both temperature and airspeed variations.
• The proposed TMFS design shows significant potential for enhancing ADS reliability.

Conclusions:

• Optimizing the physical configuration of TMFS, specifically heater-sensor distance and thermal insulation, dramatically enhances sensor sensitivity.
• The developed TMFS offers a robust solution to mitigate the risks associated with pitot tube icing in aircraft.
• This research contributes to the development of more reliable and safer aviation systems.