Impingement-Cooled Rotating Seal for Turbine Hot-Spot Heat Removal

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Solution Overview

Problem

Conventional cooling channels in rotating seals of gas turbine engines are limited by machining processes, restricting their ability to effectively dissipate heat generated at contact surfaces between rotating and stationary seals, leading to inefficient cooling and potential damage.

Innovation Solution

An impingement cooling approach is implemented using a ring-shaped rotating seal with a plenum and angled entrance and exit channels, where cooling fluid is forced to impinge against the hot side and move turbulently, forming a film to efficiently remove heat from the contact surfaces between rotating and stationary seals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If conventional cooling channels are used in rotating seals, then the structure is simple and easy to manufacture, but the cooling performance is insufficient due to limited channel locations and inability to reach hot spots

Engineering Contradiction:
Improveheat removal capabilityVSAvoidcooling channel structure
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The cooling system is segmented into multiple functional components: entrance channels for fluid supply, a plenum chamber for distribution, and exit channels for fluid discharge. This segmentation allows each component to be optimized independently, with the plenum enabling cooling fluid to reach previously inaccessible hot spots through its strategic positioning and geometry

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The cooling approach transitions from conventional linear channels to a three-dimensional plenum chamber structure. The plenum extends in multiple directions and can be positioned at various locations within the rotating seal body, enabling cooling fluid to access hot spots from multiple angles and dimensions rather than being constrained to single-path channel geometries

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Temperature

If cooling channels are positioned close to hot spots, then cooling effectiveness improves, but conventional machining processes cannot form channels in locations where oil can fully achieve the desired cooling effect

Engineering Contradiction:
Improvecooling effectiveness at hot spotsVSAvoidmachining capability
Core Design Contradiction:
TemperatureVSEase of manufacture

Solution Approach 1:

The patent replaces conventional mechanical machining processes with additive manufacturing technology. This substitution enables the creation of complex three-dimensional plenum chambers and cooling channel geometries that would be impossible or extremely difficult to produce using traditional machining methods, allowing cooling fluid to reach previously inaccessible hot spots

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

3Temperature

If compound angle cooling channels are used, then some cooling effect is achieved, but the overall cooling performance is limited by the inability to position channels optimally

Engineering Contradiction:
Improvecooling performanceVSAvoidchannel location flexibility
Core Design Contradiction:
TemperatureVSAdaptability or versatility

Solution Approach 1:

The cooling system incorporates a dynamic plenum chamber that can be positioned and oriented to adapt to different hot spot locations within the rotating seal. The plenum's flexible positioning and three-dimensional structure allow the system to adapt to varying thermal conditions and operational requirements, providing versatile cooling coverage that conventional fixed-angle channels cannot achieve

Inventive Principle:
Principle #15Dynamics

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 enhances heat removal capabilities at hot zones, preventing damage and improving engine performance by dispersing heat through the formation of cooling oil films, outperforming conventional cooling methods.

Implementation Method 1

the cooling fluid is forced by centrifugal force, during operations of the gas turbine engine in which the rotating seal rotates about the engine centerline, to enter and flow through the one or more entrance channels along radial outer surfaces to the plenum

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 2

cooling fluid exiting the one or more entrance channels and entering the plenum is expelled in a jet-like flow from the outlets to impinge against the hot side

Methodology Applied
Scientific EffectImpingement cooling:

Implementation Method 3

cooling fluid exiting the one or more entrance channels and entering the plenum is expelled in a jet-like flow from the outlets to impinge against the hot side, and subsequently move in a turbulent manner between the hot side and the relatively cool side

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 4

cooling fluid exiting the one or more entrance channels and entering the plenum is expelled in a jet-like flow from the outlets to impinge against the hot side, and subsequently move in a turbulent manner between the hot side and the relatively cool side

Methodology Applied
Scientific EffectTurbulence: Turbulence

Implementation Method 5

forming a film of cooling fluid and exiting the plenum by the one or more exit channels

Methodology Applied
Scientific EffectFilm cooling:

Data Source

PatentEP3865680B1Impingement cooled rotating seal
Publication Date: 2024.05.08 RTX CORP
  • EP3865680B1 patent drawingFigure 1
  • EP3865680B1 patent drawingFigure 2~3
  • EP3865680B1 patent drawingFigure 4~5

AI summary

A rotating seal (401) rotatable about a rotational axis (A) is provided. The rotating seal (401) includes a body (410) having a first surface (411) disposable to face the rotational axis (A) and a second surface (412) disposable to contact with a stationary element (230). The body (410) defines a cooling channel (420) including one or more entrance channels (430) respectively extending from the first surface (411), one or more exit channels (440) and a plenum (450). The plenum (450) extends circumferentially through the body (410) and has a hot side (451) adjacent to the second surface (412). The plenum (450) is fluidly interposed between the one or more entrance channels (430) and the one or more exit channels (440) whereby fluid exiting the one or more entrance channels (430) and entering the plenum (450) impinges against the hot side (451). A method of manufacturing the rotating seal (401) includes the additive manufacturing of the seal body (410).