Shaped Metering Section for Gas Turbine Cooling

Solution Overview

Problem

Conventional cooling passages in gas turbine engines face issues with kidney vortices and flow separation, leading to inefficient film cooling and increased temperature exposure of components due to hot gas entrainment, especially at high blowing ratios.

Innovation Solution

The introduction of a shaped metering section with intersecting passage walls forming a V-shape within the cooling passages, which counteracts kidney vortices and improves flow distribution to the diffusing section, reducing flow separation and turbulent mixing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional cooling passages are used, then the structure is simple, but kidney vortices and flow separation occur leading to inefficient film cooling

Engineering Contradiction:

Improvefilm cooling effectivenessVSAvoidcooling passage structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies asymmetry by introducing a shaped metering section with non-circular geometry (e.g., rectangular, oval, or polygonal cross-sections) instead of conventional circular meters. This asymmetric shaping modifies the flow patterns within the cooling passage, counteracting the formation of kidney vortices and reducing flow separation at the diffusing section, thereby improving film cooling effectiveness without requiring complex active control systems

Inventive Principle:

Principle #4Asymmetry

Solution Approach 2:

The patent changes geometric parameters of the cooling passage by varying the metering section shape, diffusing section angle, and passage aspect ratio. These parameter modifications optimize the flow distribution and pressure gradient within the passage, preventing flow separation and enhancing the uniformity of the cooling film while maintaining structural simplicity

Inventive Principle:

Principle #35Parameter changes

2Quantity of substance

If high blowing ratios are used, then more cooling flow is supplied, but hot gas entrainment increases and film cooling becomes inefficient

Engineering Contradiction:

Improvecooling flow quantityVSAvoidfilm cooling effectiveness

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The patent modifies the geometric parameters of the cooling passage, particularly the metering section shape and diffusing section configuration, to optimize flow distribution. These parameter changes enable the passage to maintain effective film cooling by controlling the injection characteristics of the cooling flow, preventing hot gas entrainment, and ensuring uniform film formation even at high blowing ratios where conventional passages would fail

Inventive Principle:

Principle #35Parameter changes

3Reliability

If conventional metering sections are used, then manufacturing is simple, but flow separation occurs at the diffusing section

Engineering Contradiction:

Improveflow distribution uniformityVSAvoidmetering section fabrication

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent employs asymmetric metering section geometries (such as rectangular, oval, or polygonal cross-sections) that are specifically designed to control flow patterns and prevent separation. These shaped meters, while requiring slightly more complex manufacturing than circular sections, can be produced using standard machining or additive manufacturing processes, achieving a balance between manufacturing feasibility and flow control performance

Inventive Principle:

Principle #4Asymmetry

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 enhances film cooling effectiveness by ensuring a uniform cooling film and reducing the likelihood of flow separation, thereby maintaining engine efficiency and extending service life even at high blowing ratios.

Implementation Method 1

Conventional cooling passages in gas turbine engines face issues with kidney vortices and flow separation, leading to inefficient film cooling and increased temperature exposure of components due to hot gas entrainment

Methodology Applied

Scientific EffectFlow separation: Flow Separation

Implementation Method 2

The introduction of a shaped metering section with intersecting passage walls forming a V-shape within the cooling passages, which counteracts kidney vortices and improves flow distribution to the diffusing section, reducing flow separation and turbulent mixing

Methodology Applied

Scientific EffectTurbulent mixing: Turbulence

Implementation Method 3

This configuration enhances film cooling effectiveness by ensuring a uniform cooling film and reducing the likelihood of flow separation, thereby maintaining engine efficiency and extending service life even at high blowing ratios

Methodology Applied

Scientific EffectFilm cooling:

Data Source

PatentUS11414999B2Cooling hole with shaped meter

Publication Date: 2022.08.16 RTX CORP

AI summary

A gas turbine engine component having a cooling passage includes a first wall defining an inlet of the cooling passage, a second wall generally opposite the first wall and defining an outlet of the cooling passage, a metering section extending downstream from the inlet, and a diffusing section extending from the metering section to the outlet. The metering section includes an upstream side and a downstream side generally opposite the upstream side. At least one of the upstream and downstream sides includes a first passage wall and a second passage wall where the first and second passage walls intersect to form a V-shape.