Variable Area Inlet Assembly for Aircraft Mass Flow Control
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Solution Overview
Problem
Existing aircraft propulsion system inlets lack the ability to efficiently adjust airflow inlet area to accommodate varying mass flow requirements based on flight conditions such as supersonic and subsonic speeds, leading to suboptimal performance.
Innovation Solution
A variable area inlet assembly with a center body structure featuring a moveable inner body and a fixed outer body, which together form a valve mechanism to regulate airflow through an inner and outer inlet passage, allowing for adjustment of airflow based on flight conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a fixed inlet structure is used, then the structure is simple and reliable, but the mass flow cannot be adjusted for different flight conditions
Solution Approach 1:
The inlet structure incorporates a moveable center body that can dynamically adjust the inlet passage area between open and closed positions, transforming a static structure into a dynamic one that adapts to different flight conditions (supersonic vs subsonic) while maintaining structural reliability
Solution Approach 2:
The inlet structure is divided into separate functional components: a fixed outer body and a moveable center body with inner body, allowing independent movement of the center body to control airflow while the outer body maintains structural integrity, thus achieving adaptability without compromising overall simplicity
2Quantity of substance
If the inlet area is increased for supersonic flight, then mass flow is sufficient, but airflow is excessive for subsonic flight conditions
Solution Approach 1:
The moveable center body enables dynamic adjustment of the inlet passage area, allowing the system to optimize air mass flow for different flight conditions - providing sufficient flow for supersonic flight while reducing flow for subsonic flight, thereby preventing energy loss from excessive airflow
Solution Approach 2:
The inlet passage area parameter is changed by moving the center body between positions, directly controlling the quantity of air entering the engine to match the mass flow requirements of different flight regimes, thus optimizing propulsion efficiency
3Productivity
If a variable area inlet is implemented, then performance across flight conditions improves, but the structural complexity increases
Solution Approach 1:
The variable area inlet uses a moveable center body that can shift between positions to change the inlet passage area, providing the necessary performance variation across flight conditions while maintaining a relatively simple overall structure through focused movability in one component
Data Source
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AI summary
An assembly (58) includes a variable area inlet (66) and an inlet duct (60). The variable area inlet (66) includes an inlet structure (68) and a center body structure (70). The inlet structure (68) extends circumferentially about the center body structure (70) with an outer inlet passage (72) radially between the center body structure (70) and the inlet structure (68). The center body structure (70) includes an outer body (98) and an inner body (100). The outer body (98) extends circumferentially about the inner body (100) with an inner inlet passage (74) radially between the inner and outer bodies (98, 100). The inner body (100) is configured to move along a centerline (30, 82) relative to the outer body (98) between a first position and a second position. The inlet duct (60) is fluidly coupled with the outer inlet passage (72) when the inner body (100) is in the first position. The inlet duct (60) is fluidly coupled with the outer inlet passage (72) and the inner inlet passage (74) when the inner body (100) is in the second position.