Conformal MEMS Air Speed Sensor for Icing and Drag Reduction
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Solution Overview
Problem
Pitot tubes used for aircraft air speed measurement are prone to icing and blockage issues, which affect accuracy and increase drag, as they are not flexible and can be easily obstructed by external matter.
Innovation Solution
A MEMS-based conformal air speed sensor system with flexible, open air channels and capacitive differential pressure sensors that measure pressure differences between airflow and static pressure, allowing for easy heating to prevent icing and reducing blockage risks by conforming to the aircraft's shape.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a Pitot tube is used for air speed measurement, then air speed can be measured, but the device is prone to icing and blockage issues
Solution Approach 1:
The patent applies this principle by using a flexible conformal sensor that can bend and adapt to the aircraft surface, preventing ice accumulation through its ability to conform tightly to the surface geometry rather than protruding into the airflow where ice can form
Solution Approach 2:
The patent inverts the traditional Pitot tube approach by using open air channels instead of enclosed tubes. This allows air to flow freely through the sensor structure, preventing blockage by external matter while still enabling pressure differential measurement for air speed detection
2Reliability
If a Pitot tube is used for air speed measurement, then air speed can be measured, but drag increases
Solution Approach 1:
The flexible conformal sensor conforms to the aircraft surface contour, creating a streamlined profile that minimizes aerodynamic drag while maintaining measurement functionality, unlike rigid protruding Pitot tubes that create wake and pressure drag
Solution Approach 2:
The conformal sensor follows the curved surface of the aircraft, creating a smooth aerodynamic profile that reduces flow separation and drag, whereas traditional Pitot tubes have sharp edges and protruding geometries that increase aerodynamic resistance
3Reliability
If a rigid structure is used for air speed measurement, then measurement can be performed, but the structure cannot conform to the aircraft surface
Solution Approach 1:
The patent uses a flexible sensor structure that can bend and conform to the curved surface of the aircraft while maintaining the integrity of the air channels and pressure sensing elements, enabling both measurement functionality and surface adaptability
Solution Approach 2:
The sensor structure is designed to be dynamically adaptable, allowing it to conform to different aircraft surface geometries and maintain functionality under various operational conditions, rather than being a fixed rigid structure
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 system provides accurate air speed measurements without icing or blockage issues, reducing drag and enhancing visibility of external matter, thus improving aerospace applications' reliability and efficiency.
Implementation Method 1
capacitive differential pressure sensors that measure pressure differences between airflow and static pressure
Implementation Method 2
allowing for easy heating to prevent icing
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
Systems and methods for measuring air speed which solve the problem of icing or blockage by creating an exterior surface on an aircraft that channels air and measures the pressure difference of the pressure through the airflow and the static pressure. This exterior surface cannot be blocked easily because air is always flowing when the aircraft is in motion, any external matter that could be on the exterior surface is readily visible, and the exterior surface can be heated to prevent icing. In addition, the exterior surface is made of a flexible material that is able to conform closely to the exterior shape of the aircraft. The preferred embodiments comprise microelectromechanical system pressure sensors placed under the air channels for measuring the pressure difference in each channel and an air speed processor for transforming the pressure differences into an air speed estimate.