Resistive-Inductive De-Icing for Aircraft Flight Control Surfaces

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Solution Overview

Problem

Existing de-icing systems for aircraft flight control surfaces, particularly pneumatic heating systems, result in parasitic losses and limited coverage, as they require direct connections to engine hot air bleed sources, leaving critical surfaces like the vertical stabilizer and nose cone unheated, and suffer from 'runback' issues when ice melts and re-freezes.

Innovation Solution

A resistive-inductive de-icing system using solenoids or coils that produce an alternating current electromagnetic field to heat flight control surfaces without direct electrical or thermal connections to the engine, allowing for 'run dry' operation and minimizing weight and fuel consumption by using on-board power sources, with sensors to monitor ambient conditions and adjust heating as needed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If pneumatic heating systems are used to heat flight control surfaces, then de-icing capability is provided, but parasitic losses occur and weight increases due to plumbing and valves

Engineering Contradiction:
Improvede-icing capabilityVSAvoidparasitic losses
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent replaces the mechanical pneumatic heating system with an electromagnetic induction heating system. The induction heating elements generate electromagnetic fields that directly induce eddy currents in the conductive flight control surfaces, eliminating the need for pneumatic plumbing, valves, and associated mechanical components. This substitution resolves the technical contradiction by providing effective de-icing capability while eliminating parasitic energy losses associated with pneumatic systems.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If pneumatic heating systems are used, then heating is provided to surfaces near engine bleed sources, but coverage is limited to those areas only

Engineering Contradiction:
Improveheating coverageVSAvoidsurface coverage range
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent divides the heating function into multiple independent induction heating elements that can be distributed across different flight control surfaces. Each heating element operates independently and can be positioned on wings, vertical stabilizers, horizontal stabilizers, and nose cones. This segmentation allows comprehensive coverage of all critical surfaces without being constrained by proximity to engine bleed sources, resolving the contradiction between reliable heating and extensive coverage range.

Inventive Principle:
Principle #1Segmentation

3Reliability

If ice is melted on de-iced surfaces, then de-icing is achieved, but runback occurs where melted water re-freezes on unheated portions

Engineering Contradiction:
Improvede-icing effectivenessVSAvoidrunback damage
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies heating to the entire flight control surface area in advance, including portions downstream of the main heating zone. By pre-heating these downstream areas, the system prevents re-freezing of melted ice water before it can cause runback damage. This preliminary action extends the heated zone beyond the minimum required for ice melting, eliminating the harmful runback effect while maintaining effective de-icing.

Inventive Principle:
Principle #10Preliminary action

4Reliability

If anti-icing fluids are applied to create shield coating, then ice formation is prevented, but additional weight and complexity are introduced

Engineering Contradiction:
Improveice preventionVSAvoidfluid system weight
Core Design Contradiction:
ReliabilityVSWeight of stationary object

Solution Approach 1:

The patent replaces the chemical anti-icing fluid system with an electromagnetic induction heating system. Instead of applying fluid coatings to prevent ice formation, the system uses induction heating elements to maintain flight control surfaces above the freezing temperature. This substitution eliminates the weight of fluid storage tanks, pumping systems, and distribution plumbing while providing reliable ice prevention through thermal management.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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

This solution effectively de-ices flight control surfaces without engine performance decrease, reduces weight and fuel consumption, and minimizes 'runback' by providing comprehensive heating coverage without parasitic losses, ensuring safer flight operations and reducing the risk of catastrophic damage.

Implementation Method 1

Each of the plurality of resistive-inductive heating elements produces an electromagnetic field and resistive heat in response to the supply alternating current (AC)

Methodology Applied
Scientific EffectResistive heating: Joule Heating

Implementation Method 2

The electromagnetic field induces an eddy current in the conductive flight control surface

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 3

The electromagnetic field induces an eddy current in the conductive flight control surface

Methodology Applied
Scientific EffectEddy current heating: Eddy Currents

Data Source

PatentEP2796372B1Resistive-inductive de-icing of aircraft flight control surfaces
Publication Date: 2019.07.24 HAMILTON SUNDSTRAND CORP
  • EP2796372B1 patent drawingFigure 1
  • EP2796372B1 patent drawingFigure 2
  • EP2796372B1 patent drawingFigure 3

AI summary

Embodiments of the disclosure include a de-icing system 100 for an aircraft. The de-icing system includes a plurality of resistive-inductive heating elements 202 inserted adjacent to a flight control surface 102 and a controlled 106 configured to provide a supply current to each of the plurality of resistive-inductive heating elements. Each of the plurality of resistive-inductive heating elements produces an electromagnetic field normal to the flight control surface 102 and resistive heat in response to the supply current. The electromagnetic field induces an eddy current in the flight control surface 102.