Gas Turbine Engine Mode Reconfiguration via Variable Bypass Duct

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Solution Overview

Problem

Existing gas turbine engine systems face challenges in efficiently changing operating modes, which can lead to stability and performance issues such as dynamic instabilities, surge, and stall when power is withdrawn or demanded suddenly.

Innovation Solution

A variable gas turbine engine design incorporating a third stream bypass duct and a control system with a display interface allows for rapid reconfiguration of engine modes, including nominal, optimum SFC, flow holding, bolter thrust, and power off-take, using turbomachinery components and sensors to manage working fluid flow and thrust settings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If gas turbine engine changes operating modes rapidly, then responsiveness and adaptability improve, but dynamic instabilities, surge, and stall occur

Engineering Contradiction:

Improvemode changing capabilityVSAvoidengine stability

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The control system anticipates mode changes and prepares the engine in advance by pre-adjusting fuel flow rates, bypass duct configurations, and turbine inlet temperatures to the target mode parameters before the actual mode transition is initiated, preventing dynamic instabilities during the transition

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The engine incorporates variable geometry components including adjustable bypass ducts, variable stator vanes, and controllable turbine inlet guide vanes that can dynamically adjust their positions during mode transitions to maintain optimal flow patterns and prevent surge and stall conditions

Inventive Principle:

Principle #15Dynamics

2Speed

If power is withdrawn or demanded suddenly, then responsiveness improves, but surge and stall occur

Engineering Contradiction:

Improvepower response speedVSAvoidengine stability

Core Design Contradiction:

SpeedVSReliability

Solution Approach 1:

The control system continuously monitors engine operating parameters including compressor outlet pressure, turbine inlet temperature, and spool speed, and automatically adjusts fuel flow and bypass valve positions in real-time to prevent surge and stall when sudden power changes are demanded

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The control system detects anticipated power demands or withdrawals and pre-adjusts operating parameters such as fuel flow rate and bypass duct opening to prepare the engine for the upcoming power change, preventing surge and stall conditions

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS9145213B2Gas turbine engine configuration interface

Publication Date: 2015.09.29 ROLLS ROYCE NORTH AMERICAN TECHNOLOGIES INC

AI summary

A gas turbine engine is disclosed which is capable of being reconfigured for one operating mode to another. A display is provided that permits a pilot or other operator to select between engine modes. One aspect is the ability to provide variable cooling that can be controlled by various devices. The variable cooling features can be used with devices such as cooled turbine components like vanes and/or blades. Devices can be used to reconfigure the performance and/or operability of a gas turbine engine.