Turbine Cooling Air Plenum Reverse Flow Aperture Design

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Solution Overview

Problem

Existing cooling air configurations in gas turbine engines are inefficient in effectively distributing cooling air to turbine components, leading to reduced cooling efficiency, especially as the air flows from the high-energy front to the rear, where its pressure and flow rate are diminished, limiting its ability to cool effectively.

Innovation Solution

A gas turbine engine design featuring a plenum with aperture sets that allow cooling air to flow from the rear towards the front, contrary to the main gas path, with strategically positioned aperture sets to optimize cooling air distribution and flow rates, ensuring better air usage and cooling efficiency across multiple turbine stages.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If cooling air flows from the front to the rear in the plenum, then the cooling air can access turbine components, but the pressure and flow rate diminish towards the rear, reducing cooling efficiency

Engineering Contradiction:

Improveturbine component temperatureVSAvoidcooling air flow rate

Core Design Contradiction:

TemperatureVSQuantity of substance

Solution Approach 1:

The patent inverts the conventional cooling air flow direction by introducing cooling air at the rear plenum and allowing it to flow forward through aperture sets to the turbine components. This reverse flow direction ensures that cooling air maintains higher pressure and flow rate at the rear where it is introduced, rather than losing pressure as it travels from front to rear as in conventional designs.

Inventive Principle:

Principle #13The other way round (Inversion)

2Temperature

If cooling air is introduced at the front of the plenum, then it can reach turbine components, but by the time it reaches the rear, its pressure and flow rate are significantly reduced

Engineering Contradiction:

Improveturbine component temperatureVSAvoidcooling air pressure

Core Design Contradiction:

TemperatureVSStress or pressure

Solution Approach 1:

The patent introduces cooling air at the rear plenum instead of the front, inverting the flow direction. This ensures that cooling air is introduced when pressure is highest and maintains that pressure as it flows forward through the aperture sets to the turbine components, rather than losing pressure over the distance as in conventional front-to-rear flow designs.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent divides the plenum into multiple sections with aperture sets positioned at different locations, allowing cooling air to be distributed to different turbine stages at optimized pressure levels. The segmentation of the cooling air path enables pressure management at different positions along the flow path.

Inventive Principle:

Principle #1Segmentation

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 cooling efficiency by maintaining higher air pressure and flow rates, reducing heat exposure time, and improving temperature control across turbine stages, with improved velocity and distribution of cooling air, leading to better control of tip clearance and overall engine performance.

Implementation Method 1

conveying cooling air in a plenum surrounding a main gas path in the turbine section, from a rear of the turbine section towards a front of the turbine section

Methodology Applied

Scientific EffectPressure gradient: Pressure Gradient

Implementation Method 2

a plurality of aperture sets interspaced from one another between the front and the rear, and the aperture sets providing fluid flow communication from the plenum to the gas path

Methodology Applied

Scientific EffectFluid flow:

Implementation Method 3

leaking a plurality of cooling flows from the plenum to the main gas path, at a plurality of axially interspaced positions

Methodology Applied

Scientific EffectConvection: Convection

Implementation Method 4

enhances cooling efficiency by maintaining higher air pressure and flow rates, reducing heat exposure time, and improving temperature control across turbine stages

Methodology Applied

Scientific EffectHeat transfer:

Data Source

PatentUS10941709B2Gas turbine engine and cooling air configuration for turbine section thereof

Publication Date: 2021.03.09 PRATT & WHITNEY CANADA CORP

AI summary

The gas turbine engine can have a gas path extending in serial flow communication across a compressor, a combustion chamber, and a turbine, the turbine having at least one multistage turbine section having a front toward the combustion chamber and a rear opposite the front, a plenum radially outward of the gas path, and a plurality of aperture sets interspaced from one another between the front and the rear, the aperture sets providing fluid flow communication from the plenum to the gas path, and a cooling air path having an outlet fluidly connected to the plenum at the rear of the plenum.