Variable Area Inlet Assembly for Aircraft Mass Flow Adaptation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing aircraft propulsion system inlets lack an efficient mechanism to adapt to varying airflow mass flow requirements based on operational parameters such as modes of operation and aircraft maneuvers.

Innovation Solution

A variable area inlet assembly with a movable inlet door and multiple inlet passages that can adjust the airflow inlet area by translating between closed and open positions, allowing for tailored mass flow management.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a fixed airflow inlet area is used, then the structure is simple, but the system cannot adapt to varying mass flow requirements

Engineering Contradiction:
Improveadaptability to varying mass flow requirementsVSAvoidinlet structure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The inlet structure incorporates a movable inlet door that can translate between closed and open positions to dynamically adjust the airflow inlet area. This dynamic configuration allows the system to adapt to varying mass flow requirements while maintaining a relatively simple overall structure, resolving the contradiction between adaptability and complexity.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If a variable airflow inlet area mechanism is added, then adaptability improves, but device complexity increases

Engineering Contradiction:
Improvemass flow adaptation capabilityVSAvoidinlet assembly complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The inlet structure is segmented into multiple inlet passages with a movable inlet door that can selectively open or close individual passages. This segmentation allows for granular control of airflow while keeping each individual component simple, thereby improving adaptability without proportionally increasing overall device complexity.

Inventive Principle:
Principle #1Segmentation

3Productivity

If the inlet door translates to adjust airflow area, then mass flow management is optimized, but the mechanism requires more components

Engineering Contradiction:
Improvemass flow management efficiencyVSAvoidnumber of inlet passages
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The movable inlet door serves multiple functions: it acts as a sealing element, a flow control mechanism, and a structural support. By making this single component multi-functional, the system achieves optimized mass flow management without requiring additional separate components for each function, thus improving productivity without proportionally increasing device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 variable area inlet effectively manages airflow mass flow according to changing operational conditions, enhancing performance and efficiency by optimizing air intake for different flight speeds and maneuvers.

Implementation Method 1

The variable area inlet effectively manages airflow mass flow according to changing operational conditions, enhancing performance and efficiency by optimizing air intake for different flight speeds and maneuvers

Methodology Applied
Scientific EffectFluid flow control:

Data Source

PatentEP4407166B1Aircraft propulsion system with variable area inlet
Publication Date: 2025.12.03 ROHR INC
  • EP4407166B1 patent drawingFigure 1
  • EP4407166B1 patent drawingFigure 2
  • EP4407166B1 patent drawingFigure 3A~3C

AI summary

An assembly for an aircraft includes a variable area inlet (62, 78) for an aircraft propulsion system (22). The variable area inlet (62, 78) extends along a longitudinal centerline (34, 90). The variable area inlet (62, 78) includes an inlet structure (80), an inlet door (82), an inner inlet passage (84), and an outer inlet passage (86). The inlet door (82) is configured to axially translate from a closed position to an open position along the longitudinal centerline (34, 90). The inlet door (82) is configured to close the outer inlet passage (86) when the inlet door (82) is in the closed position. The inlet door (82) is configured to open the outer inlet passage (86) when the inlet door (82) is in the open position. The inner inlet passage (84) extends into the variable area inlet (62, 78) from a leading edge (92) of the inlet structure (80). The outer inlet passage (86) extends through the inlet structure (80) to the inner inlet passage (84).