Seal Runner Helical Groove Cooling for Oil Slinger Heat Transfer

Solution Overview

Problem

Current oil slinger systems for gas turbine engines have limitations in heat transfer efficiency due to restricted cooling liquid flow paths and contact areas, leading to suboptimal convective cooling performance.

Innovation Solution

The oil slinger system incorporates a seal runner with an annular radial member and an outer axially extending member featuring a plurality of helical grooves and ridges, which directs cooling liquid in a helical flow path, increasing contact area and residence time, and includes a lower oil passage for lubrication, enhancing axial convective cooling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If smooth inner surfaces are used in seal runners, then manufacturing is simple, but heat transfer efficiency is limited

Engineering Contradiction:

Improveheat transfer efficiencyVSAvoidsurface geometry complexity

Core Design Contradiction:

TemperatureVSDevice complexity

Solution Approach 1:

The seal runner surface is divided into different zones with different geometries: smooth surfaces in some areas and helical grooves/ridges in other areas. This local differentiation allows the surface to have varying heat transfer characteristics - enhanced heat transfer where grooves are present and simpler geometry where smooth surfaces are used, resolving the contradiction between heat transfer efficiency and manufacturing complexity.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

Helical grooves and ridges are introduced to create curved, three-dimensional surface features instead of flat smooth surfaces. These curved geometries promote turbulent flow and increase surface area for heat transfer, improving thermal performance while the helical pattern can be manufactured using standard machining processes.

Inventive Principle:

Principle #14Spheroidality (Curvature)

2Temperature

If cooling liquid flow path is restricted, then device structure is simple, but convective cooling performance is suboptimal

Engineering Contradiction:

Improveconvective cooling performanceVSAvoidflow path structure

Core Design Contradiction:

TemperatureVSDevice complexity

Solution Approach 1:

Helical grooves and ridges are introduced to create curved, three-dimensional surface features instead of flat smooth surfaces. These curved geometries promote turbulent flow and increase surface area for heat transfer, improving thermal performance while the helical pattern can be manufactured using standard machining processes.

Inventive Principle:

Principle #14Spheroidality (Curvature)

Solution Approach 2:

The cooling liquid flow is transitioned from a primarily axial two-dimensional path to a three-dimensional helical path that incorporates circumferential motion. This dimensional change increases the flow path length and contact area between cooling liquid and seal runner surface, enhancing convective cooling without requiring additional axial length.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Temperature

If axial length is increased to improve cooling, then heat transfer efficiency improves, but device length increases

Engineering Contradiction:

Improveheat transfer efficiencyVSAvoidaxial length

Core Design Contradiction:

TemperatureVSLength of moving object

Solution Approach 1:

The cooling liquid flow is transitioned from a primarily axial two-dimensional path to a three-dimensional helical path that incorporates circumferential motion. This dimensional change increases the flow path length and contact area between cooling liquid and seal runner surface, enhancing convective cooling without requiring additional axial length.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

Helical grooves and ridges are introduced to create curved, three-dimensional surface features instead of flat smooth surfaces. These curved geometries promote turbulent flow and increase surface area for heat transfer, improving thermal performance while the helical pattern can be manufactured using standard machining processes.

Inventive Principle:

Principle #14Spheroidality (Curvature)

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 configuration significantly improves heat transfer efficiency by increasing the cooling liquid's contact area and residence time, allowing for more effective heat removal from the seal runner without increasing its axial length, with preliminary studies indicating an 80% improvement over conventional systems.

Implementation Method 1

the plurality of helical grooves direct the cooling liquid along the proximal surface of the outer axially extending member in a helical cooling liquid flow direction

Methodology Applied

Scientific EffectHelical flow:

Implementation Method 2

convectively cooling the oil slinger system, wherein the oil slinger system comprises a seal runner

Methodology Applied

Scientific EffectConvection: Convection

Data Source

PatentEP3954878A1Seal runner with passive heat transfer augmentation features

Publication Date: 2022.02.16 RTX CORP

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AI summary

Oil slinger systems include a seal runner (108; 508) comprising an annular radial member (109; 509) having a radius (R) and an outer axially extending member (116; 516) having an axial length (L), wherein a proximal surface (562) of the outer axially extending member comprising a plurality of helical grooves (564). Methods of radial convective cooling include pumping a cooling liquid through the oil slinger system and convectively cooling the oil slinger.