Flush Surface Sensor for Droplet Size Differentiation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Ice formation on aircraft surfaces increases weight and drag, leading to higher stall speeds, reduced lift and thrust, and affects controllability, and existing detection methods are inadequate for differentiating ice accretion caused by varying supercooled water droplet sizes.
Innovation Solution
A system comprising sensors with exposed conductors to detect current flow changes due to ice accretion, coupled with a controller to activate icing protection systems and generate alerts based on detected water particle sizes, and a particle size analyzer to differentiate ice accretion regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional ice detection methods are used, then ice formation can be detected, but droplet size differentiation cannot be achieved
Solution Approach 1:
The airfoil surface is divided into multiple sensing zones with sensors positioned at different locations (leading edge, mid-chord, trailing edge). Each sensor detects ice accretion in its specific zone, enabling differentiation of droplet sizes based on which zones are affected, thus achieving measurement precision without requiring a single complex sensor
Solution Approach 2:
The system transitions from detecting only the presence of ice to detecting the spatial distribution of ice accretion across multiple zones along the chord. By adding the dimensional aspect of position along the airfoil chord, the system can infer droplet size information from the pattern of ice detection across zones
2Reliability
If sensors are positioned to detect all water particles, then comprehensive detection is achieved, but droplet size differentiation is lost
Solution Approach 1:
Different sensor zones are optimized for detecting different droplet size ranges. The leading edge zone detects smaller droplets, while zones further aft detect larger droplets. Each zone has specific detection characteristics tailored to the local flow conditions and droplet impingement patterns, enabling size differentiation while maintaining reliable detection across all zones
Solution Approach 2:
The system uses feedback from multiple sensor zones to determine droplet size. When sensors in specific zones detect ice accretion, this feedback information is processed to infer the size range of impinging droplets, allowing the system to maintain reliable detection while achieving size differentiation through pattern recognition
3Reliability
If ice protection systems are activated early, then ice formation is prevented, but unnecessary activation increases energy consumption
Solution Approach 1:
The ice protection system activation is made dynamic rather than static. Instead of continuous or always-on operation, the system dynamically activates heating elements in specific zones based on real-time ice detection feedback from sensors. This allows the system to maintain high reliability by activating only when and where needed, thereby reducing unnecessary energy consumption
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
Effectively differentiates ice accretion caused by different supercooled water droplet sizes, enabling timely alerts and control of icing protection systems to prevent ice formation, thereby maintaining aircraft performance and safety.
Implementation Method 1
A sensor having a sensing surface region is mounted at a mounting location of the airfoil such that the sensing surface region is flush with a surrounding adjacent surface of the airfoil. Water particles of sizes less than or equal to a predetermined threshold do not impinge the sensor surface region at the mounting location when the aircraft is in flight. A sensor driver provides an excitation signal to the sensor. A signal detector detects a sensor signal responsive to the provided excitation signal, the detected sensor signal indicative of water particles exceeding the predetermined threshold impinging the sensing surface region.
Implementation Method 2
In some embodiments, the sensing surface region is mechanically coupled to a resonant cavity. The resonant cavity can have a resonant frequency that is indicative of ice accretion upon the surface region of the sensor.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Apparatus and associated methods relate to differentiating ice accretion caused by different supercooled water droplets on an airfoil (12) of an aircraft. A sensor (22) having a sensing surface region (42) is mounted at a mounting location of the airfoil (12) such that the sensing surface region (42) is flush with a surrounding adjacent surface of the airfoil (12). Water particles of sizes less than or equal to a predetermined threshold do not impinge the sensor surface region (42) at the mounting location when the aircraft is in flight. A sensor driver provides an excitation signal to the sensor (22). A signal detector (43) detects a sensor signal responsive to the provided excitation signal. The sensor signal is indicative of water particles exceeding the predetermined threshold impinging the sensing surface region (42). In some embodiments, the sensing surface region (42) is mechanically coupled to a resonant cavity (22C). In other embodiments, the sensor (22) is a surface resistance sensor configured to sense surface resistance.