Variable Area Aircraft Inlet for Adaptive Mass Flow Control
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Solution Overview
Problem
Existing aircraft propulsion systems lack an efficient mechanism to adapt the airflow inlet area to varying mass flow requirements based on different flight conditions and throttle settings.
Innovation Solution
A variable area inlet assembly with an outer and inner airflow passages, regulated by pivotable doors and actuators, allowing for dynamic adjustment of airflow through the inlet duct to accommodate changing mass flow demands.
Engineering Contradictions & Design Principles
Engineering 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 across different flight conditions
Solution Approach 1:
The inlet structure employs movable doors (first door and second door) that can pivot between different positions to dynamically adjust the airflow inlet area. The doors are connected to actuators and linkages that enable them to change position in response to different flight conditions, allowing the system to adapt its geometry rather than being fixed
Solution Approach 2:
The inlet structure is divided into multiple independent components: an outer airflow inlet passage, an inner airflow inlet passage, a first door for the outer passage, and a second door for the inner passage. This segmentation allows each door to be controlled independently to achieve different airflow configurations suitable for various operating modes
2Adaptability or versatility
If a variable area inlet with multiple passages and doors is implemented, then adaptability to different flight conditions is improved, but the device complexity increases
Solution Approach 1:
The inlet structure serves multiple functions through its variable geometry: it can operate in different airflow modes (outer passage only, inner passage only, or both passages) to accommodate various flight conditions including takeoff, cruise, and landing. The same basic structure with doors and passages handles all these different operational requirements
Solution Approach 2:
The inner airflow inlet passage is nested within the outer airflow inlet passage, with the second door positioned inside the first door's rotation path. This nested arrangement allows compact packaging of the variable geometry mechanism while maintaining independent control of both airflow passages
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
Enables optimal airflow management across different flight modes and throttle settings, enhancing propulsion efficiency and reducing noise generation.
Implementation Method 1
The valve includes a first door configured to pivot between a closed position and an open position
Implementation Method 2
The actuator may be attached to the slider. The slider may be mated with and may be configured to translate along the track. Each of the linkages may be between and may be pivotably connected to the slider and a respective one of the doors
Data Source
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AI summary
A propulsion system assembly (20) includes a variable area inlet (66) and an inlet duct (60). The variable area inlet (66) includes an outer airflow inlet passage (72), an inner airflow inlet passage (74), an inlet structure (70) and a center body structure (68). The outer airflow inlet passage (72) is between the inlet structure (70) and the center body structure (68). The inner airflow inlet passage (74) is formed within the center body structure (68). The center body structure (68) includes a valve (124A) configured to regulate air flow through the inner airflow inlet passage (74). The valve (124A) includes a first door (188A) configured to pivot between a closed position and an open position. The inlet duct (60) is configured to receive air from the outer airflow inlet passage (72) when the first door (188A) is in the closed position. The inlet duct (60) is configured to receive air from the outer airflow inlet passage (72) and the inner airflow inlet passage (74) when the first door (188A) is in the open position.