Turbine Blade Tip Cooling via Segmented Microcircuits

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Solution Overview

Problem

As Rotor Inlet Temperature (RIT) increases, blade tip erosion becomes a weak point in the design of high pressure turbine blades, and existing cooling technologies for turbine engine components typically achieve cooling effectiveness between 0.5 and 0.7, which is insufficient to prevent material melting and burning.

Innovation Solution

A tip cooling system utilizing serpentine microcircuits on both the suction and pressure sides of turbine engine components, with separate cooling circuits for leading and trailing edges, and film cooling to maintain low-temperature coolant supply, reducing thermal load and enhancing heat transfer through film blowing and convective cooling at the tip.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If Rotor Inlet Temperature (RIT) is increased to improve power output, then power generation increases, but blade tip erosion worsens and cooling effectiveness decreases

Engineering Contradiction:
Improvepower outputVSAvoidblade tip erosion resistance
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The tip cooling system divides the cooling function into separate segments: a first cooling circuit for the pressure side tip region and a second cooling circuit for the suction side tip region. This segmentation allows independent optimization of cooling on each side, enabling effective heat dissipation at higher RIT without tip erosion

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The cooling system applies local quality by providing dedicated cooling circuits specifically to the tip regions rather than uniform cooling throughout. The first and second cooling circuits are positioned to address the specific thermal conditions and erosion risks at the pressure and suction sides of the tip respectively

Inventive Principle:
Principle #3Local quality

2Device complexity

If conventional cooling technology is used, then device complexity is reduced, but cooling effectiveness is insufficient (0.5-0.6) to prevent material melting

Engineering Contradiction:
Improvecooling system complexityVSAvoidcooling effectiveness
Core Design Contradiction:
Device complexityVSTemperature

Solution Approach 1:

The tip cooling system employs a nested structure where microcircuits are integrated within the blade tip structure itself. The first and second cooling circuits are embedded in the pressure and suction side walls respectively, creating a compact nested arrangement that achieves high cooling effectiveness (above 0.7) without adding significant external complexity

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The invention transitions from conventional two-dimensional cooling surfaces to three-dimensional microcircuits embedded within the tip structure. This dimensional change allows coolant to flow through the volume of the tip rather than just along the surface, dramatically improving cooling effectiveness from 0.5-0.6 to above 0.7

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

3Temperature

If microcircuit cooling is implemented to achieve cooling effectiveness above 0.7, then temperature control improves, but device complexity and manufacturing difficulty increase

Engineering Contradiction:
Improvecooling effectivenessVSAvoidmanufacturing complexity
Core Design Contradiction:
TemperatureVSEase of manufacture

Solution Approach 1:

The tip cooling system merges the cooling function with the structural walls of the blade tip. The first cooling circuit is integrated into the pressure side wall and the second cooling circuit into the suction side wall, combining structural and thermal management functions. This merging reduces manufacturing complexity compared to adding separate external cooling components

Inventive Principle:
Principle #5Merging (Combining)

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 proposed cooling system effectively prevents blade tip erosion by maintaining low metal temperatures, achieving higher cooling effectiveness and reducing tip leakage losses, while simplifying manufacturing with a compact design.

Implementation Method 1

enhancing heat transfer through film blowing and convective cooling at the tip

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 2

film cooling to maintain low-temperature coolant supply, reducing thermal load

Methodology Applied
Scientific EffectFilm cooling:

Data Source

PatentEP1882820B1Microcircuit cooling and blade tip blowing
Publication Date: 2011.03.16 UNITED TECH CORP
  • EP1882820B1 patent drawingFigure 1~3
  • EP1882820B1 patent drawingFigure 4~6
  • EP1882820B1 patent drawingFigure 7~9

AI summary

A turbine engine component (90) has an airfoil portion (110) having a pressure side (116), a suction side (118), a leading edge (112), a trailing edge (114), and a tip (134). The component (90) further has a first cooling microcircuit (100) embedded in a pressure side wall, a second cooling microcircuit (102) embedded in a suction side wall, and a system for cooling the tip comprising a first tip cooling microcircuit receiving cooling fluid from the first cooling microcircuit (100) and a second tip cooling microcircuit receiving cooling fluid from the second cooling microcircuit (102).