Self-Actuated Compressor Bleed Valve to Minimize Flutter

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Solution Overview

Problem

Conventional bleed valves in gas turbine engines are inefficient in reducing rotational energy during start-up and present packaging challenges due to their bulkiness and tendency to flutter, which affects their operational effectiveness and integration in streamlined applications.

Innovation Solution

A self-actuated bleed valve design featuring a flapper assembly with a pivotally mounted flapper and a biasing member, where the flapper is angled to create a larger sealing area and a compact footprint, allowing direct connection between fluid paths without additional ducts, and utilizing a split valve body for simplified installation and reduced flapper flutter through a balanced force mechanism.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If conventional bleed valves are used to reduce rotational energy during start-up, then energy reduction is achieved, but the valve becomes bulky and causes packaging challenges

Engineering Contradiction:
Improverotational energyVSAvoidvalve size
Core Design Contradiction:
Use of energy by moving objectVSVolume of moving object

Solution Approach 1:

The flapper is designed to dynamically adjust its angle relative to the valve body inlet based on fluid flow conditions. During start-up, the flapper angles toward the inlet to maximize flow and reduce rotational energy requirements. During steady-state operation, the flapper returns to a neutral position. This dynamic positioning allows the valve to achieve effective flow control with a more compact design compared to conventional fixed-geometry valves.

Inventive Principle:
Principle #15Dynamics

2Productivity

If conventional bleed valves are used for flow control, then flow regulation is achieved, but the valve experiences flapper flutter affecting operational effectiveness

Engineering Contradiction:
Improveflow controlVSAvoidflapper stability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The flapper's angular position is dynamically changed based on operating conditions. The flapper angles toward the valve body inlet during high-flow start-up conditions and returns to neutral during steady-state operation. This parameter change optimizes flow control effectiveness while maintaining flapper stability by reducing the angle between the flapper and incoming fluid flow, thereby minimizing flutter.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If the flapper is angled towards the valve body inlet, then flow control effectiveness is improved, but the sealing area increases requiring larger valve components

Engineering Contradiction:
Improveflow control effectivenessVSAvoidsealing area
Core Design Contradiction:
ProductivityVSArea of moving object

Solution Approach 1:

The flapper dynamically angles toward the valve body inlet only during start-up conditions when maximum flow control effectiveness is needed. During steady-state operation, the flapper returns to a neutral position, minimizing the effective sealing area. This dynamic adjustment allows the valve to achieve high flow control effectiveness during critical periods without permanently requiring larger sealing surfaces or valve components.

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

The solution reduces rotational energy requirements during engine start-up, minimizes flapper flutter, and enables compact packaging, enhancing the operational efficiency and integration of bleed valves in gas turbine engines.

Implementation Method 1

A biasing member, such as a spring, is coupled between the flapper and the outlet end of the valve body, and exerts a biasing force that urges the flapper toward the open position

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

fluid moving through the valve body exerts force on the flapper, urging the flapper towards the closed position

Methodology Applied
Scientific EffectFluid pressure: Pressure Increase

Data Source

PatentEP3118436B1Bleed valves for gas turbine engines
Publication Date: 2021.06.02 HAMILTON SUNDSTRAND CORP
  • EP3118436B1 patent drawingFigure 1
  • EP3118436B1 patent drawingFigure 2
  • EP3118436B1 patent drawingFigure 3~4

AI summary

A bleed valve (100) for a gas turbine engine compressor has a valve body (102) and a flapper (116). The valve body (102) defines a flow path and includes a flapper seat (112). The flow path extends through the valve body (102). The flapper (116) is pivotally connected to the valve body (102) and is movable between a closed position and an open position. In the closed position the flapper (116) seats against the flapper seat (112) and blocks the flow path. In the open position the flapper (116) is angled towards the valve body inlet such that fluid moving through the valve body (102) exerts force on the flapper (116), urging the flapper (116) towards the closed position. A biasing member operatively connects the valve body (102) and the flapper (116) and has a biasing force urging the flapper toward the open position.