Offtake Scoop Radial Flow for Gas Turbine Bleed Pressure Recovery

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Solution Overview

Problem

In gas turbine engines, the airflow extracted for cooling the turbine blades undergoes significant pressure loss due to vortexing, reducing the pressure of the bleed air and impacting the cooling efficiency of downstream components.

Innovation Solution

The implementation of an offtake scoop and inner shroud design that directs airflow radially inward toward the bleed opening, using an upstream and downstream wall with a channel and optionally a guide vane to improve airflow laminarity and reduce pressure loss, thereby enhancing bleed pressure recovery and cooling efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If bleed air is extracted from the compressor for turbine cooling, then turbine cooling efficiency is improved, but pressure loss due to vortexing increases

Engineering Contradiction:

Improveturbine cooling efficiencyVSAvoidpressure loss

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The flow path is segmented into distinct regions: the compressor passage, the bleed opening, the offtake scoop channel, and the turbine cooling passage. This segmentation allows each region to be optimized independently, with the offtake scoop channel specifically designed to minimize vortexing and pressure loss while maintaining adequate bleed air flow for turbine cooling.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The offtake scoop acts as an intermediary component between the compressor and the bleed opening. It includes a channel with an upstream wall, downstream wall, and optionally a guide vane, which mediates the airflow transition and reduces harmful vortexing effects, thereby minimizing pressure loss while maintaining cooling efficiency.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If bleed air pressure is reduced due to vortexing, then airflow extraction is maintained, but cooling efficiency of downstream components deteriorates

Engineering Contradiction:

Improveairflow extractionVSAvoidcooling efficiency

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The offtake scoop channel is designed with specific geometric parameters including an upstream wall, downstream wall, and optionally a guide vane, which modify the airflow parameters. These geometric parameters are optimized to reduce vortexing and pressure loss, thereby maintaining both airflow extraction and cooling efficiency.

Inventive Principle:

Principle #35Parameter changes

3Ease of manufacture

If conventional compressor design is used, then manufacturing simplicity is maintained, but pressure loss and vortexing are significant

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidpressure loss

Core Design Contradiction:

Ease of manufactureVSLoss of energy

Solution Approach 1:

The offtake scoop channel is designed to dynamically adapt to the airflow conditions in the compressor. The channel geometry, including the upstream and downstream walls and optional guide vane, is configured to work with the natural flow patterns, minimizing additional complexity while effectively reducing pressure loss and vortexing.

Inventive Principle:

Principle #15Dynamics

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 design improves airflow into the bleed opening, increasing bleed air pressure and reducing backflow, which enhances the cooling efficiency of the turbine blades and maintains a sufficient pressure margin for effective cooling.

Implementation Method 1

the airflow extracted for cooling the turbine blades undergoes significant pressure loss due to vortexing

Methodology Applied

Scientific EffectVortexing:

Implementation Method 2

This bleed air is routed to the turbine(s) for cooling the turbine(s)... the airflow extracted for cooling the turbine blades undergoes significant pressure loss

Methodology Applied

Scientific EffectPressure loss: Pressure Drop

Implementation Method 3

using an upstream and downstream wall with a channel and optionally a guide vane to improve airflow laminarity

Methodology Applied

Scientific EffectLaminar flow: Laminar Flow

Implementation Method 4

A portion of the high pressure air in the compressor flows through the opening and into an inner passageway of the shaft

Methodology Applied

Scientific EffectPressure gradient: Pressure Gradient

Data Source

PatentUS11725530B1Offtake scoops for bleed pressure recovery in gas turbine engines

Publication Date: 2023.08.15 GENERAL ELECTRIC CO

AI summary

An example gas turbine engine includes a compressor including a casing defining a passageway and a shaft extending through the passageway. The shaft drivingly coupling the compressor and a turbine of the gas turbine engine. The shaft has an opening to receive airflow from the passageway. The gas turbine engine also includes an inner shroud, stator vanes coupled to and extending radially between the casing and the inner shroud, and an offtake scoop disposed on a downstream side of the inner shroud. The offtake scoop has a channel to direct the airflow radially inward toward the opening in the shaft.