Temperature-Based Flow Restrictor for Aircraft Nacelle Deicing

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Solution Overview

Problem

Existing thermal management systems for aircraft nacelles face overheating issues due to temperature fluctuations in bleed air, which can lead to component degradation and reduced operational efficiency.

Innovation Solution

A thermal management system that includes a passively actuated flow restrictor, configured downstream of the pressure regulator, which selectively restricts the flow of bleed gas based on temperature thresholds to prevent overheating, ensuring consistent heat transfer and maintaining component integrity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If hot bleed air is directed to the nacelle body for heating and de-icing, then ice build-up is prevented, but temperature fluctuations can cause the nacelle body and/or components to overheat

Engineering Contradiction:
Improvede-icing effectivenessVSAvoidnacelle body temperature
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The flow restrictor changes the flow parameter of bleed air based on temperature conditions. When the nacelle body temperature exceeds a threshold, the restrictor reduces the flow rate of hot bleed air to prevent overheating, while allowing full flow during cold conditions for effective de-icing

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The thermal management system incorporates temperature sensing and feedback control through the flow restrictor. The restrictor responds to temperature fluctuations by automatically adjusting bleed air flow, creating a closed-loop control system that maintains temperature within safe operating limits

Inventive Principle:
Principle #23Feedback

2Temperature

If a flow restrictor is added to control temperature, then overheating is prevented, but device complexity increases

Engineering Contradiction:
Improvenacelle body temperature controlVSAvoidthermal management system complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The flow restrictor is designed as a self-regulating component that automatically adjusts bleed air flow based on temperature conditions without requiring external control systems. The restrictor itself performs the temperature-dependent flow control function, eliminating the need for additional sensors, actuators, or control logic

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The flow restrictor acts as an intermediary component between the bleed air source and the nacelle body. It mediates the temperature conflict by selectively restricting flow when temperatures are high, serving as a passive temperature-dependent flow control element that simplifies the overall control architecture

Inventive Principle:
Principle #24Intermediary (Mediator)

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 effectively mitigates overheating by varying the flow of bleed gas according to temperature, thereby extending component lifespan and maintaining operational efficiency across varying conditions.

Implementation Method 1

temperature fluctuations of the bleed air can cause the nacelle body and/or components of the thermal management system to overheat

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

direct relatively hot compressed air, bled from a gas turbine engine compressor, to a nacelle body to thereby heat that body

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP3219957B1Thermal management system for deicing aircraft with temperature based flow restrictor
Publication Date: 2021.05.12 ROHR INC
  • EP3219957B1 patent drawingFigure 1
  • EP3219957B1 patent drawingFigure 2~3
  • EP3219957B1 patent drawingFigure 4

AI summary

Assemblies are provided for an aircraft with a gas turbine engine (12). One assembly includes a body (18) such as an inlet nose lip (18) of a nacelle (14) for the gas turbine engine (12). This assembly also includes a thermal management system (16) that includes a duct (58), a regulator (60) and a flow restrictor (62). The thermal management system (16) is configured to direct a flow of bleed gas through the duct (58) from the gas turbine engine (12) to the body (18) for substantially preventing ice buildup on the body (18). The regulator (60) is configured to affect the flow of bleed gas downstream of the regulator (60). The flow restrictor (62) is configured to selectively restrict the flow of bleed gas through the duct (58) when a temperature of the flow of bleed gas is greater than a threshold temperature (Tthreshold).