Aircraft Pitot Probe Dual Heating Wire Power Distribution

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Solution Overview

Problem

Current Pitot probes require high maximum electrical power for heating to prevent water accumulation and maintain accurate total pressure measurements, especially in icing conditions, leading to excessive energy consumption.

Innovation Solution

The probe features two separate heating wires with independent power distribution based on the temperature of each part, allowing for optimized heating by prioritizing power allocation to areas that need it most, thereby reducing overall energy consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a single heating resistance is used to heat the entire probe, then the probe can be heated uniformly, but the maximum electrical power consumption is excessive

Engineering Contradiction:
Improveprobe temperatureVSAvoidelectrical power consumption
Core Design Contradiction:
TemperatureVSUse of energy by moving object

Solution Approach 1:

The heating resistance is divided into two independent segments: a first heating resistance for heating the first part of the probe and a second heating resistance for heating the second part of the probe. This segmentation allows independent control of power distribution to different probe sections, enabling reduced maximum power consumption while maintaining necessary temperature levels in each segment based on local requirements.

Inventive Principle:
Principle #1Segmentation

2Reliability

If heating power is increased to prevent water accumulation in all conditions, then measurement accuracy is maintained, but energy consumption increases excessively

Engineering Contradiction:
Improvemeasurement accuracyVSAvoidelectrical power consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

Different heating strategies are applied to different parts of the probe based on their specific operational conditions. The first part of the probe receives heating power according to its temperature requirements and environmental conditions, while the second part receives appropriate heating independently. This local quality approach ensures each section maintains sufficient temperature for accurate measurements without requiring the entire probe to be heated to maximum power levels.

Inventive Principle:
Principle #3Local quality

3Device complexity

If a single heating wire is used for the entire probe, then the structure is simple, but the power distribution cannot be optimized for different probe parts

Engineering Contradiction:
Improveheating system structureVSAvoidpower distribution efficiency
Core Design Contradiction:
Device complexityVSUse of energy by moving object

Solution Approach 1:

The heating system is segmented into two independent heating wires or resistance elements, each可控 independently. This segmentation increases structural complexity slightly but enables optimized power distribution where each heating element can be controlled separately based on the specific thermal requirements and environmental conditions of its respective probe section, significantly improving power distribution efficiency.

Inventive Principle:
Principle #1Segmentation

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 approach reduces the maximum power necessary for heating, ensuring accurate total pressure measurements while minimizing energy usage, even in challenging conditions like icing, by efficiently managing power distribution between the Pitot tube and mast.

Implementation Method 1

The heating of the probe is commonly carried out by means of a heating resistance made in the form of a wire wound in the body of the probe

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 2

The stream of air located upstream of the tube is gradually slowed down until it reaches almost zero speed at the tube inlet. Slowing the air speed increases the air pressure. This increased pressure forms the total pressure Pt of the airflow

Methodology Applied
Scientific EffectBernoulli effect: Bernoulli Effect

Data Source

PatentEP2772764B1Probe for measuring the total pressure of a flow and method for implementing the probe
Publication Date: 2016.01.20 THALES SA
  • EP2772764B1 patent drawingFigure 1~2
  • EP2772764B1 patent drawingFigure 3~5
  • EP2772764B1 patent drawingFigure 6

AI summary

The probe (10) has a pitot tube (14), and two separate heating wires (31, 32) heated separately, where one heating wire is intended to heat the pitot tube, and the other heating wire is intended to heat a mast (15). A distributing unit (35) distributes a given maximum power to each one of the two heating wires as a function of the current temperature of each of the pitot tube and the mast. A fixing unit includes a base (23) and a screw (25) for fixing the probe to the skin of an aircraft, where the mast connects the pitot tube to the fixing unit. An independent claim is also included for a method for using a probe for measuring the total pressure of an airflow.