Flush-Mounted AOA Sensor Using Thermal Cooling Rate
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional angle-of-attack (AOA) sensors on aircraft are prone to damage from bird strikes and maintenance operations, affecting aircraft performance due to their protruding design.
Innovation Solution
A non-protruding AOA sensor system that measures airspeed by determining the rate of cooling of a heated metallic layer integrated into the aircraft fuselage, using precision heating circuitry and thermometry to regulate temperature, and includes features for moisture detection and fluid film measurement, with a design that minimizes mechanical damage and thermal expansion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a protruding sensor design is used to measure AOA, then the sensor can effectively detect airflow direction, but the sensor becomes susceptible to damage from bird strikes and maintenance operations
Solution Approach 1:
The patent replaces the traditional mechanical protruding sensor with a flush-mounted sensor system that uses thermal measurement principles. Instead of mechanically interacting with airflow through a protruding element, the system uses a heated element flush with the fuselage surface and measures cooling rates to determine AOA, thereby eliminating mechanical damage susceptibility while maintaining measurement capability
Solution Approach 2:
The patent changes the measurement parameter from direct mechanical force detection to thermal cooling rate detection. By heating an element flush-mounted in the fuselage and measuring its rate of cooling in different airflow conditions, the system determines AOA without requiring a protruding mechanical structure, thus improving reliability while reducing damage susceptibility
2Object-affected harmful factors
If a flush-mounted sensor design is used to reduce damage risk, then the sensor becomes more resistant to mechanical damage, but the measurement precision may be reduced
Solution Approach 1:
The patent applies local quality by creating a controlled thermal environment around the flush-mounted heated element. By insulating the element and controlling its thermal properties locally, the system ensures that cooling rate measurements accurately reflect airflow conditions despite the flush-mounted configuration, thereby maintaining measurement precision while achieving damage resistance
Solution Approach 2:
The system uses feedback by continuously monitoring the cooling rate of the heated element and using this information to determine AOA. The measurement system processes thermal data in real-time, comparing cooling rates under different airflow conditions to accurately calculate AOA, thus maintaining measurement precision with the flush-mounted design
3Device complexity
If traditional protruding AOA sensors are used, then the system is simple in design, but the sensors are prone to damage and require frequent maintenance
Solution Approach 1:
The patent applies universality by integrating multiple functions into the flush-mounted thermal sensor system. The same heated element serves both as a thermal measurement device for AOA determination and as a protective element flush with the fuselage surface, eliminating the need for separate protective structures and reducing overall system complexity while improving reliability
Solution Approach 2:
The patent replaces the complex mechanical protruding sensor system with a simpler thermal measurement system. By using thermal conductivity and cooling rate measurements instead of mechanical force detection, the system reduces structural complexity while improving operational continuity through enhanced durability
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution provides a robust and sensitive AOA measurement system that is less susceptible to damage, maintains aircraft performance, and operates effectively at low airspeeds, offering improved reliability and accuracy compared to traditional sensors.
Implementation Method 1
measures airspeed by determining the rate of cooling of a heated metallic layer integrated into the aircraft fuselage
Implementation Method 2
using precision heating circuitry and thermometry to regulate temperature
Data Source
AI summary
A sensor assembly includes a metallic layer positioned at least partially on an insulating material coupled to a fuselage of an aircraft. The sensor assembly further includes a pair of terminals arranged at opposite ends of the metallic layer and a temperature probe thermally coupled to the metallic layer. The metallic layer is heated by a heater thermally coupled to the metallic layer. The temperature probe is used to determine a rate of cooling for the metallic layer, responsive to an air flow over the metallic layer.