Bleed Air Offtake Assembly Pressure Relief

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Solution Overview

Problem

Existing bleed air systems in gas turbine engines have limitations in aerodynamics and performance, which can be improved upon to enhance efficiency and functionality.

Innovation Solution

The design incorporates a gas turbine engine with a bleed air offtake assembly that includes a relief opening in the outer-duct wall, allowing for fluid communication between the conduit outlet and the interior of the duct. This assembly features a conduit with a pressure-relief mechanism that alleviates excess pressure, optimizing airflow and reducing vibrations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a conventional bleed air system is used, then the system can provide bleed air for engine functions and aircraft functions, but the aerodynamics and performance can be improved upon

Engineering Contradiction:
Improvebleed air system efficiencyVSAvoidaerodynamic performance
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The bleed air system is segmented into multiple independent conduits (first conduit and second conduit) with separate control mechanisms. The first conduit connects to the first compressor stage while the second conduit connects to the second compressor stage, allowing independent control and optimization of bleed air extraction from different compression stages, thereby improving overall system efficiency and aerodynamic performance

Inventive Principle:
Principle #1Segmentation

2Productivity

If bleed air is extracted from the duct, then airflow is reduced, but pressure differentials cause vibrations

Engineering Contradiction:
Improvebleed air extraction capabilityVSAvoidvibrations
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

A pressure differential sensor is installed to continuously monitor the pressure difference between the duct interior and the conduit exterior. This feedback signal is fed to a control system that adjusts the position of the adjustable damper in real-time, modulating the bleed air extraction rate to maintain optimal pressure differentials and minimize vibrations while maximizing bleed air extraction capability

Inventive Principle:
Principle #23Feedback

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 enhances the aerodynamic performance and efficiency of the bleed air system by managing pressure differentials and reducing vibrations, thereby improving the overall functionality of the gas turbine engine.

Implementation Method 1

managing pressure differentials

Methodology Applied
Scientific EffectPressure differential: Pressure Gradient

Implementation Method 2

the conduit outlet is in fluid communication with inside the duct via the relief opening

Methodology Applied
Scientific EffectFluid communication:

Implementation Method 3

a bleed air offtake assembly (40) connected to the duct (30) such that some of the air flow (F) may be drawn from the duct (30) by the offtake assembly (40)

Methodology Applied
Scientific EffectPressure differential: Pressure Gradient

Data Source

PatentEP4116560B1Bleed air offtake assembly for a gas turbine engine
Publication Date: 2025.04.16 PRATT & WHITNEY CANADA CORP
  • EP4116560B1 patent drawingFigure 1A
  • EP4116560B1 patent drawingFigure 1B~1C
  • EP4116560B1 patent drawingFigure 2~3

AI summary

A gas turbine engine (10A; 10B; 10C) comprising: a duct (30) extending about an axis (CL), the duct (30) including an outer-duct wall (32) having an interior-duct surface (32i) circumscribing an interior of the duct (30) and an exterior-duct surface (32e) radially outward of the interior-duct surface (32i) relative to the axis (CL), the outer-duct wall (32) defining an offtake opening (34) extending from the interior-duct surface (32i) to the exterior-duct surface (32e), the offtake opening (34) in fluid communication between an offtake location (L1) inside the duct (30) and outside the duct (30); and a bleed air offtake assembly (40) including: an air line (60) in fluid communication with inside the duct (30) via the offtake opening (34), the air line (60) having a first-line end defining a line inlet (62) proximate to the outer-duct wall (32) and a second-line end spaced from the first-line end; a valve (70) located outside the duct (30) and fluidly connected to the air line (60) via the second-line end, and a conduit (80) having a conduit inlet (82) in fluid communication with inside the air line (60) at a resonance location (L2) between the first-line end and the second-line end upstream of the valve (70), and a conduit outlet (84) in fluid communication with inside the duct (30) at a relief location (L3) spaced from the offtake location (L1).