Tail Cone Ejector for Gas Turbine Cable Cooling

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Gas turbine engine conductive cables face temperature issues due to proximity to high-energy exhaust air flows, with existing cooling systems relying on limited bypass air or bleed air, which may not provide sufficient cooling, especially after engine shutdown.

Innovation Solution

An ejector assembly is integrated into the cooling system, utilizing a tail cone with a nozzle section and an ejector body to entrain cooling air from an external source with exhaust air, ensuring effective cooling of conductive cables through a conduit and electric motor, even after engine shutdown.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If cooling systems rely on limited bypass air or bleed air, then the system structure is simple, but the cooling effectiveness is insufficient especially after engine shutdown

Engineering Contradiction:
Improvecable temperatureVSAvoidcooling air flow
Core Design Contradiction:
TemperatureVSQuantity of substance

Solution Approach 1:

The patent applies pneumatic principles by using the ejector assembly to generate high-velocity exhaust air flow that creates a vacuum effect, automatically drawing cooling air through the conduit without mechanical fans or pumps. This pneumatic system ensures continuous cooling air supply even after engine shutdown by utilizing stored exhaust gas pressure.

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The cooling system is designed to be self-regulating, where the exhaust air flow from the engine automatically controls the cooling air intake through the ejector effect. The system adjusts its own cooling capacity based on engine operation status without requiring external control mechanisms, ensuring adequate cooling during both operation and shutdown phases.

Inventive Principle:
Principle #25Self-service

2Temperature

If ejector assembly is integrated into cooling system, then cooling effectiveness is improved, but device complexity increases

Engineering Contradiction:
Improvecable temperatureVSAvoidcooling system structure
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The ejector assembly is integrated with the existing exhaust system and cooling conduit, merging the exhaust gas flow path with the cooling air intake path. This combination allows the exhaust system to serve dual purposes: propulsion/exhaust and cooling generation, reducing the need for separate cooling components.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The ejector assembly acts as an intermediary device that converts exhaust gas kinetic energy into a vacuum effect, mediating between the exhaust system and the cooling air source. This intermediary component enables effective cooling without requiring direct mechanical connection to the engine or additional power sources.

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 solution provides efficient cooling of conductive cables by leveraging external air sources and exhaust air entrainment, ensuring reliable operation and reduced cable temperatures, even when the engine is not in use.

Implementation Method 1

the ejector assembly configured to entrain the cooling air flow via the exhaust air flow

Methodology Applied
Scientific EffectEntrainment: Entrainment

Implementation Method 2

an ejector body defining a mixing section

Methodology Applied
Scientific EffectMixing:

Implementation Method 3

the cooling air flow configured to cool the plurality of conductive cables

Methodology Applied
Scientific EffectConvection cooling: Convection

Data Source

PatentEP4194679B1Tail cone ejector for power cable cooling system in a gas turbine engine
Publication Date: 2024.11.20 RTX CORP
  • EP4194679B1 patent drawingFigure 1A
  • EP4194679B1 patent drawingFigure 1B
  • EP4194679B1 patent drawingFigure 2

AI summary

An ejector assembly (400; 500) for a cooling system (300; 600) of a gas turbine engine (110) may comprise: a tail cone (122; 410; 510) having a tail cone outlet (414; 518) in fluid communication with a cooling air flow of the cooling system; an ejector body (420; 520) defining a mixing section (404; 504), a constant area section (406; 506), and a diffuser section (408; 508); and a nozzle section (402; 502) in fluid communication with an exhaust air flow of the gas turbine engine, the ejector assembly configured to entrain the cooling air flow via the exhaust air flow.