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

Abstract

A high-speed and high-temperature calorimetric solid-state thermal mass flow sensor (TMFS) design was proposed and its sensitivity to temperature and airflow speed were numerically assessed. The sensor operates at 573.15 Kelvin (300 °C), measuring speeds up to 265 m/s, and is customized to be a transducer for an aircraft Air Data System (ADS). The aim was to enhance the system reliability against ice accretion on pitot tubes’ pressure intakes, which causes the system to be inoperative and the aircraft to lose protections that ensure its safe operation. In this paper, the authors assess how the distance between heater and thermal sensors affects the overall TMFS sensitivity and how it can benefit from the inclusion of a thermal barrier between these elements. The results show that, by increasing the distance between the heater and temperature sensors from 0.1 to 0.6 mm, the sensitivity to temperature variation is improved by up to 80%, and that to airspeed variation is improved by up to 100%. In addition, adding a thermal barrier made of Parylene-N improves it even further, by nearly 6 times, for both temperature and air speed variations.

Multifunctional Integration of Optical Fibers and Nanomaterials for Aircraft Systems

“…In aircraft operation, the environmental monitoring is crucial for the navigation and instrumentation equipment, where the Air Data System is responsible to provide the flight data to the crew [ 22 ]. Considering an important technology for the system’s navigation, especially on the external measurements of speed, the Pitot tube technology is widely employed [ 23 ].…”

“…Considering an important technology for the system’s navigation, especially on the external measurements of speed, the Pitot tube technology is widely employed [ 23 ]. Such a sensor uses the air pressure in dynamic and static intake conditions, in which the operation in the harsh environments of the flight conditions can lead to freezing of the device’s orifice that can ultimately lead to critical issues in the sensor reading and even accidents [ 22 ]. To that extent, the Federal Aviation Administration provides instructions for the atmospheric conditions that can lead to such critical issues in the instrumentation, which also indicates the necessity of measuring the atmospheric/environmental conditions in-flight [ 22 ].…”

High-Performance Airflow Sensors Based on Suspended Ultralong Carbon Nanotube Crossed Networks

“…High-performance airflow sensors are in huge demand in many fields such as aerospace industry, weather forecasting, environmental monitoring, chemical and biological engineering, health monitoring, and wearable smart devices, etc. − These applications usually have strict requirements on the performance of airflow sensors in terms of sensitivity, response time, detection threshold, and detection range, etc. − However, traditional airflow sensors based on hot-wire or hot-film mechanisms can hardly meet these requirements, and their shortcomings such as complicated fabrication processes (heavily depend on microelectro mechanical systems (MEMS)-based chips) and high power-consumption are also fatal. − Among airflow sensors with various working mechanisms, piezoresistive sensors are promising candidates due to their simple fabrication and easy signal acquisition. , However, the sensing performance and practicality of previously reported piezoresistive sensors are still far from satisfactory due to the unsatisfactory performance of their functional materials as well as coarse structural designs.…”

Structural Design of Dual-Type Thin-Film Thermopiles and Their Heat Flow Sensitivity Performance

“…A heat flux sensor is a kind of device or instrument that can detect and monitor the heat flux density in real time and convert it into an electrical signal for output [ 6 , 7 , 8 ]. It is widely used in the technical field of national defense, and the technology of measuring heat flux density has made great progress.…”