Gas Turbine Rotor Bushing Adaptive Airflow Temperature Metering

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Gas turbine engines face challenges in regulating temperature differentials across rotor stages due to limited airflow regulation, leading to inefficient cooling and thermal gradient mitigation in compressor and turbine sections.

Innovation Solution

The rotor stack design incorporates sized hot-side and cold-side grooves to provide a predetermined temperature airflow mixture, with an optional anti-vortex tube system within the inner plenum, allowing for precise control of secondary airflow through a bushing and counterbore interface, enabling a desired mixed airflow for improved cooling and thermal management.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If airflow is sourced from a single location in the compressor section, then the system is simple to implement, but the temperature regulation precision is insufficient

Engineering Contradiction:
Improvetemperature regulation precisionVSAvoidairflow source configuration
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent divides the single airflow source into multiple discrete airflow sources at different axial locations in the compressor section. Each source location provides air at a different temperature, allowing precise control of the mixed airflow temperature by adjusting the relative flow rates from each source. This segmentation enables temperature regulation precision that cannot be achieved with a single source location.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If the rotor stack uses traditional bolted attachment without specialized airflow control, then the manufacturing is simpler, but the airflow metering precision is insufficient

Engineering Contradiction:
Improveairflow metering precisionVSAvoidrotor stack assembly
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent introduces grooves as intermediary features within the bolted attachment structure of the rotor stack. These grooves are specifically designed to meter and control the airflow passing through the rotor stack, enabling precise airflow regulation without requiring complex additional components. The grooves integrate the airflow control function into the existing structural assembly, maintaining ease of manufacture while achieving precise metering.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If minimal cooling airflow is used to maintain system simplicity, then the device complexity is reduced, but the cooling effectiveness is insufficient

Engineering Contradiction:
Improvecooling effectivenessVSAvoidcooling flow regulation system
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements a dynamic cooling flow regulation system where the cooling airflow is not fixed but can be adjusted based on operational requirements. The system uses controllable flow paths and metering features that allow the cooling flow rate to be optimized for different operating conditions, thereby achieving high cooling effectiveness without requiring an overly complex fixed-system design. The dynamics principle allows the system to adapt cooling performance to match actual thermal demands.

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 enhances airflow regulation, achieving a temperature difference of 100-200°F (55.6-111.1°C) between hot-side and cold-side airflow, providing more precise cooling for turbine sections and conditioning for compressor sections, thereby improving efficiency and reducing thermal stress.

Implementation Method 1

sized hot-side and cold-side grooves to provide a predetermined temperature airflow mixture

Methodology Applied
Scientific EffectFluid flow mixing:

Implementation Method 2

providing more precise cooling for turbine sections

Methodology Applied
Scientific EffectConvection cooling: Convection

Implementation Method 3

achieving a temperature difference of 100-200°F (55.6-111.1°C) between hot-side and cold-side airflow

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 4

an optional anti-vortex tube system within the inner plenum

Methodology Applied
Scientific EffectVortex suppression: Vortex Ring

Data Source

PatentEP3851632B1Gas turbine engine rotor stack with bushing having adaptive airflow temperature metering
Publication Date: 2023.11.08 RTX CORP
  • EP3851632B1 patent drawingFigure 1
  • EP3851632B1 patent drawingFigure 2
  • EP3851632B1 patent drawingFigure 3

AI summary

A rotor stack for a gas turbine engine includes a first rotor disk (62A) with a first rotor spacer arm (82), the first rotor spacer arm (82) having a first flange (100) with an outboard flange surface (102) and an inboard flange surface (104), a first hole (106) along an axis (T) through the first flange (100), the first hole (106) having a counterbore (108) in the outboard flange surface (102); a second rotor disk (62B) with a web (80B) having a second hole (152) along the axis (T); a third rotor disk (62C) with a third rotor spacer arm (84), the third rotor spacer arm (84) having a third flange (140) with an outboard flange surface (142) and an inboard flange surface (144), a third hole (146) along the axis (T) through the third flange (140), the third hole (146) having a counterbore (148) in the inboard flange surface (144); and a bushing (184) with a tubular body (192) and a flange (186) that extends therefrom, the tubular body (192) comprising at least one axial groove (188) along an outer diameter thereof, the bushing (184) extends through the first hole (106), the second hole (152) and partially into the counterbore (148) in the inboard flange surface (144) of the third hole (146).