Ram Air Turbine Integrated Heat Exchanger Cooling

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Solution Overview

Problem

High power Ram Air Turbine (RAT) systems in aircraft generate excessive heat, which cannot be effectively cooled by the airstream alone, necessitating the use of liquid cooling systems with separate heat exchangers that protrude into the airstream, complicating the design and increasing weight and maintenance costs.

Innovation Solution

An integrated heat exchanger system within the RAT system, comprising a gearbox with a speed-increasing gear train and a generator, utilizes a coolant circuit with recirculating coolant and cooling fins on the housing to dissipate heat efficiently, eliminating the need for a separate heat exchanger and reducing the number of components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a separate heat exchanger is used to cool the high-power RAT system, then heat dissipation capability is improved, but device complexity and weight increase

Engineering Contradiction:

Improveheat dissipation capabilityVSAvoidsystem complexity

Core Design Contradiction:

TemperatureVSDevice complexity

Solution Approach 1:

The patent combines the heat exchanger with the housing structure of the RAT system, integrating cooling functionality into the existing structural component. This merging eliminates the need for a separate heat exchanger assembly, thereby reducing device complexity while maintaining effective heat dissipation capability through the integrated fins and coolant circuit.

Inventive Principle:

Principle #5Merging (Combining)

2Temperature

If a separate heat exchanger is used to cool the high-power RAT system, then heat dissipation capability is improved, but weight increases

Engineering Contradiction:

Improveheat dissipation capabilityVSAvoidsystem weight

Core Design Contradiction:

TemperatureVSWeight of moving object

Solution Approach 1:

By merging the heat exchanger functions into the housing structure, the patent eliminates the weight of separate heat exchanger components, coolant reservoirs, and associated mounting hardware. The housing itself serves as the heat dissipation structure, reducing overall system weight while maintaining adequate cooling capacity for the high-power generator and gearbox.

Inventive Principle:

Principle #5Merging (Combining)

3Temperature

If a separate heat exchanger is used to cool the high-power RAT system, then heat dissipation capability is improved, but maintenance costs increase

Engineering Contradiction:

Improveheat dissipation capabilityVSAvoidmaintenance costs

Core Design Contradiction:

TemperatureVSEase of repair

Solution Approach 1:

The integration of the heat exchanger into the housing creates a unified structure with fewer separate components, connections, and interfaces. This reduces the number of potential failure points and simplifies maintenance procedures, as technicians need to service fewer separate systems. The consolidated design lowers maintenance costs by reducing complexity and the number of replaceable components.

Inventive Principle:

Principle #5Merging (Combining)

4Device complexity

If the number of components is reduced by integrating the heat exchanger, then device complexity is reduced, but heat dissipation capability may worsen

Engineering Contradiction:

Improvenumber of componentsVSAvoidheat dissipation capability

Core Design Contradiction:

Device complexityVSTemperature

Solution Approach 1:

The patent applies local quality by incorporating cooling fins directly onto the housing surfaces that are in contact with or near heat-generating components. This localized heat dissipation approach ensures that heat is efficiently transferred from critical areas (generator and gearbox) to the surrounding airstream, maintaining effective heat dissipation capability despite the reduction in overall system complexity.

Inventive Principle:

Principle #3Local quality

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 integrated heat exchanger effectively cools the high-power RAT system, reducing weight, size, and maintenance costs while enhancing reliability and heat dissipation, leading to a more efficient and cost-effective power generation solution.

Implementation Method 1

cooling fins on the housing to dissipate heat efficiently

Methodology Applied

Scientific EffectConvection: Convection

Implementation Method 2

cooling fins on the housing to dissipate heat efficiently

Methodology Applied

Scientific EffectThermal radiation: Thermal Radiation

Implementation Method 3

utilizes a coolant circuit with recirculating coolant and cooling fins on the housing to dissipate heat efficiently

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentUS8864448B2Ram air turbine with integrated heat exchanger

Publication Date: 2014.10.21 GENERAL ELECTRIC CO

AI summary

A ram air turbine system for generating electrical power in an aircraft when the system is exposed to an airstream exterior of the aircraft. The ram air turbine system includes a turbine, a housing defining an interior, a gearbox having a speed-increasing gear train, and a generator.