Adaptive Air Duct Flange Connection for Hot, Tight Engine Spaces

Solution Overview

Problem

Conventional bolted joint configurations for aircraft engine ducting face challenges due to space limitations and exposure to high temperatures, leading to reduced lifespan and performance losses.

Innovation Solution

An air duct interface system utilizing a first and second air duct with coupling flanges, clamping blocks, and adjusting blocks, which apply compound forces to secure the connection while minimizing moment forces on bolts, allowing installation in confined spaces and maintaining durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional bolted joint configurations are used to attach ducting to the aircraft engine, then the connection can be secured, but the bolts are subjected to high temperatures which reduces lifespan and may introduce performance losses

Engineering Contradiction:

Improveconnection durabilityVSAvoidbolt temperature exposure

Core Design Contradiction:

ReliabilityVSTemperature

Solution Approach 1:

The coupling flange is divided into multiple segments (first coupling flange with first and second portions, second coupling flange with multiple portions) that can be independently positioned and secured. This segmentation allows the connection to be made away from the high-temperature path while still achieving a secure bond between ducting components.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces coupling flanges as intermediary components between the ducting and the aircraft engine. These flanges serve as mediators that transfer loads without requiring bolts to be directly in the high-temperature gas path, thereby protecting the bolts from extreme thermal exposure while maintaining connection integrity.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If conventional bolted joint configurations are used, then the ducting can be connected, but space and access limitations in some engine-nacelle combinations make installation difficult

Engineering Contradiction:

Improveconnection securityVSAvoidinstallation accessibility

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The coupling flange is divided into multiple segments (first coupling flange with first and second portions, second coupling flange with multiple portions) that can be independently positioned and secured. This segmentation allows the connection to be made away from the high-temperature path while still achieving a secure bond between ducting components.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent extends the coupling flange structure in multiple spatial dimensions (first portion extending in first direction, second portion extending in second direction, etc.) to create a multi-dimensional connection system. This allows the connection to accommodate limited installation space by utilizing available space in multiple directions rather than requiring a single large access area.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Ease of manufacture

If bolts are located in the path of high temperature gases, then the connection can be made, but the lifespan of the bolted joint is reduced

Engineering Contradiction:

Improveconnection feasibilityVSAvoidbolted joint lifespan

Core Design Contradiction:

Ease of manufactureVSDuration of action of stationary object

Solution Approach 1:

The patent extracts the bolts from the high-temperature gas path by positioning them in portions of the coupling flange that extend away from the sealing face and the hot gas flow. The bolts secure the flange segments without being directly exposed to the thermal environment, thereby maintaining connection feasibility while preserving bolt lifespan.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces coupling flanges as intermediary components between the ducting and the aircraft engine. These flanges serve as mediators that transfer loads without requiring bolts to be directly in the high-temperature gas path, thereby protecting the bolts from extreme thermal exposure while maintaining connection integrity.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentEP4596846A1Adaptive flange connection of air ducts of a gas turbine engine

Publication Date: 2025.08.06 PRATT & WHITNEY CANADA CORP

Figure 1A~1B
Figure 2A
Figure 2B

AI summary

An air duct interface (112) is disclosed herein. The air duct interface includes a first air duct (202) including a first opening (216) and a first coupling flange (210) disposed circumferentially around the first opening (216), a second air duct (204) including a second opening and a second coupling flange (224) circumferentially surrounding the second opening, a first clamping block (206) coupled to the first coupling flange (210) by a first bolt (220), wherein the second coupling flange (224) is disposed between a portion of the first clamping block (206) and the first coupling flange (210), and a first adjusting block (208) coupled to the first coupling flange (210) by a second bolt (220), the first adjusting block (208) engaging the first coupling flange (210) and the second coupling flange (224).