Multi-scale Turbulators for Gas Turbine Cooling Channels

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Solution Overview

Problem

Existing turbulators in gas turbine airfoils do not effectively increase surface area, boundary layer mixing, and control boundary layer separation in cooling channels, leading to inefficient heat transfer and thermal stress.

Innovation Solution

The implementation of multi-scale turbulators with features such as parallel ridges and valleys, smaller ridges, grooves, bumps, and dimples on the inner surfaces of cooling channels, which increase the convective surface area and enhance boundary layer mixing by controlling separation and turbulence.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If conventional single-scale turbulators are used in cooling channels, then the structure is simple, but the surface area increase and boundary layer mixing effectiveness are insufficient

Engineering Contradiction:
Improveconvective surface areaVSAvoidturbulator structure complexity
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The patent implements multi-scale turbulation features where smaller-scale features (ridges, grooves, bumps, dimples) are nested on and between larger-scale features. This nesting approach increases the convective surface area at multiple levels while maintaining a unified turbulator structure that can be integrated into the cooling channel geometry.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The turbulator structure is segmented into multiple distinct features at different scales including primary ridges, secondary grooves, tertiary bumps, and quaternary dimples. Each segment serves to increase surface area and enhance mixing at different spatial scales, collectively improving heat transfer efficiency.

Inventive Principle:
Principle #1Segmentation

2Productivity

If conventional turbulators are used, then the cooling channel structure remains simple, but the boundary layer mixing and heat transfer efficiency are insufficient

Engineering Contradiction:
Improveheat transfer efficiencyVSAvoidturbulator feature complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

Different regions of the turbulator structure have different local features optimized for specific functions. For example, ridges create primary turbulence, grooves enhance secondary mixing, bumps increase local surface area, and dimples control boundary layer separation. Each local feature is positioned to address specific heat transfer needs at that location.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent transitions from single-scale two-dimensional turbulator surfaces to multi-scale three-dimensional features with varying heights, depths, and spatial distributions. This dimensional complexity enhances boundary layer mixing and heat transfer by creating turbulence at multiple spatial scales simultaneously.

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

3Reliability

If multi-scale turbulation features are implemented, then surface area and boundary layer mixing are enhanced, but the manufacturing complexity increases

Engineering Contradiction:
Improvecooling effectivenessVSAvoidturbulator manufacturing ease
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

Multiple turbulation features at different scales are merged into a single integrated turbulator component that can be manufactured as one piece. This combining approach maintains the complex multi-scale geometry needed for effective heat transfer while enabling production through single-step processes like investment casting or additive manufacturing.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent optimizes the geometric parameters of multi-scale features (sizes, spacing, depths, angles) to achieve effective heat transfer enhancement while considering manufacturing constraints. By carefully selecting parameter ranges, the design balances cooling effectiveness with manufacturability through conventional turbine blade manufacturing processes.

Inventive Principle:
Principle #35Parameter changes

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 enhances heat transfer efficiency by increasing the surface area and improving coolant contact with the channel surfaces, reducing thermal stress and the volume of air diverted for cooling.

Implementation Method 1

The present invention provides improved turbulators with features at multiple scales in combinations that increase surface area, increase boundary layer mixing, and control boundary layer separation

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 2

The implementation of multi-scale turbulators with features such as parallel ridges and valleys, smaller ridges, grooves, bumps, and dimples on the inner surfaces of cooling channels, which increase the convective surface area and enhance boundary layer mixing by controlling separation and turbulence

Methodology Applied
Scientific EffectTurbulence: Turbulence

Data Source

PatentEP3399150B1Turbine component with multi-scale turbulation features
Publication Date: 2024.06.12 RTX CORP
  • EP3399150B1 patent drawingFigure 1
  • EP3399150B1 patent drawingFigure 2~4
  • EP3399150B1 patent drawingFigure 5~8

AI summary

Multi-scale turbulation features, including first turbulators (46, 48) on a cooling surface (44), and smaller turbulators (52, 54, 58, 62) on the first turbulators. The first turbulators may be formed between larger turbulators (50). The first turbulators may be alternating ridges (46) and valleys (48). The smaller turbulators may be concave surface features such as dimples (62) and grooves (54), and/or convex surface features such as bumps (58) and smaller ridges (52). An embodiment with convex turbulators (52, 58) in the valleys (48) and concave turbulators (54, 62) on the ridges (46) increases the cooling surface area, reduces boundary layer separation, avoids coolant shadowing and stagnation, and reduces component mass.