Baffle Insert Trip Strips Enhance Gas Turbine Cooling

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Solution Overview

Problem

Gas turbine engine airfoil sections, particularly those downstream of the combustor, face high thermal and mechanical loads due to high combustion temperatures, leading to reduced service life and increased maintenance costs, necessitating effective cooling techniques.

Innovation Solution

The use of a baffle insert with trip strips and ribs configured in various patterns within the airfoil's cooling cavities to create vortices and enhance convective cooling, increasing the heat transfer coefficient and reducing operating temperatures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If high combustion temperatures are used to increase power output, then the power and efficiency of the gas turbine engine is improved, but the thermal and mechanical loads on turbine airfoils increase, reducing service life and reliability

Engineering Contradiction:

Improvepower outputVSAvoidservice life of turbine airfoils

Core Design Contradiction:

PowerVSReliability

Solution Approach 1:

A baffle insert is introduced as an intermediary component within the cooling cavity. The baffle insert with its trip strips and ribs modifies the cooling airflow pattern, creating vortices that enhance heat transfer from the airfoil interior surfaces to the cooling air, thereby protecting the airfoil from high thermal loads while maintaining high combustion temperatures for power generation

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces simple passive cooling passages with an active vortex-generating cooling system. The trip strips and ribs on the baffle insert create turbulent vortices that significantly enhance convective heat transfer coefficients, substituting a more complex flow dynamics mechanism to achieve better thermal protection

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Device complexity

If conventional cooling passages are used without flow enhancement features, then the device complexity is low, but the cooling efficiency is insufficient to protect airfoils from high thermal loads

Engineering Contradiction:

Improvecooling passage structureVSAvoidairfoil operating temperature

Core Design Contradiction:

Device complexityVSTemperature

Solution Approach 1:

The trip strips are configured in a spiral arrangement around the baffle insert, creating curved vortex flow paths. This spiral geometry generates rotational vortices that enhance mixing and heat transfer efficiency, allowing the cooling system to achieve lower airfoil temperatures with a relatively simple baffle insert structure

Inventive Principle:

Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent adds a third dimension to the cooling flow by creating three-dimensional vortices through the spiral trip strips and vertical ribs. This transforms the cooling from a simple two-dimensional passage flow to a three-dimensional vortex flow, significantly enhancing heat transfer without requiring multiple separate cooling passages

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Productivity

If spiral trip strips are added to create vortices, then convective cooling efficiency is enhanced, but the device complexity and manufacturing difficulty increase

Engineering Contradiction:

Improvecooling efficiencyVSAvoidmanufacturing of baffle insert

Core Design Contradiction:

ProductivityVSEase of manufacture

Solution Approach 1:

The patent combines multiple flow enhancement features (spiral trip strips, vertical ribs, and baffle geometry) into a single integrated baffle insert component. This merging of features into one piece reduces the number of separate parts to manufacture and assemble, offsetting the increased complexity of the spiral geometry with overall structural integration

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

This configuration enhances convective cooling efficiency, extends the service life of airfoil components, and reduces the cooling airflow requirements, while minimizing stress concentrations and pressure drops.

Implementation Method 1

the plurality of trip strips extend upwardly from the exterior surface of the baffle insert in a spiral configuration, configured to create a plurality of vortices at the exterior of the baffle insert

Methodology Applied

Scientific EffectVortex: Vortex Ring

Implementation Method 2

enhance convective cooling, increasing the heat transfer coefficient

Methodology Applied

Scientific EffectConvection: Convection

Implementation Method 3

at least one rib extending upwardly from the exterior surface of the baffle insert, configured to terminate the plurality of vortices

Methodology Applied

Scientific EffectTurbulence: Turbulence

Data Source

PatentEP3181820B1A gas turbine engine component with a baffle insert

Publication Date: 2020.02.05 UNITED TECH CORP

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AI summary

A component of a gas turbine engine, the component having: an internal cooling cavity extending through an interior of the component; a baffle insert (32) configured to be inserted into the internal cooling cavity; a plurality of trip strips (40) extending upwardly from an exterior surface of the baffle insert; and at least one rib extending upwardly from the exterior surface (38) of the baffle insert, wherein the plurality of trip strips and the at least one rib (42) are spaced from an interior surface of the internal cooling cavity.