Adjustable Bleed Air Inlet with Boundary Layer Flow Guide
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Solution Overview
Problem
Existing devices for extracting bleed air from aircraft engines create flow resistance due to their rigid inlet openings, even when no bleed air is required, leading to inefficiencies in air extraction.
Innovation Solution
An adjustable air inlet with a movable design and a flow guide means that separates boundary layer flows, allowing for variable inlet cross-section settings and minimizing flow resistance by diverting boundary layer flows into a bypass duct, using a combination of channel-shaped and plate-shaped elements with an actuator for precise control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a rigid inlet opening is used for bleed air extraction, then the structure is simple and stable, but flow resistance increases and air extraction efficiency decreases
Solution Approach 1:
The patent applies the dynamics principle by making the inlet cross-section adjustable through movable elements (first and second elements) that can change position relative to each other. This allows the inlet to adapt its geometry dynamically - closing when bleed air is not needed to minimize flow resistance, and opening when bleed air extraction is required. The actuator enables this dynamic adjustment, transforming a static rigid structure into a dynamic adaptive one that optimizes flow characteristics.
Solution Approach 2:
The patent implements parameter changes by varying the inlet cross-section area and orientation angle. The movable elements can change the inlet cross-section from fully open to fully closed positions, and can also adjust the orientation relative to the flowing air. These parameter changes allow optimization of the inlet geometry to minimize flow resistance while maintaining extraction capability when needed.
2Adaptability or versatility
If the inlet cross-section is always open for bleed air extraction, then bleed air can be extracted when needed, but flow resistance increases even when no bleed air is required
Solution Approach 1:
The dynamic adjustment mechanism allows the inlet to transition between open and closed states based on operational requirements. When bleed air is not required, the movable elements close the inlet cross-section to eliminate flow resistance. When bleed air extraction is needed, the inlet opens to the appropriate degree. This dynamic behavior enables the system to maintain adaptability while minimizing energy losses during periods when extraction is not required.
Solution Approach 2:
The inlet operation follows periodic action by alternating between open and closed states based on the periodic requirements of the aircraft engine for bleed air. The actuator controls the inlet to be open during periods when cooling or air conditioning is needed, and closed during periods when these systems are not required, creating a periodic operational pattern that balances extraction capability with flow resistance minimization.
3Loss of energy
If the inlet cross-section is closed to reduce flow resistance, then energy losses decrease, but the ability to extract bleed air is reduced
Solution Approach 1:
The dynamic inlet design resolves this contradiction by making the inlet cross-section adjustable rather than fixed. The system can dynamically transition between closed (minimizing flow resistance) and open (maximizing extraction rate) states based on real-time operational requirements. This dynamic capability allows the system to optimize between energy efficiency and productivity as conditions change, rather than being constrained to a single fixed state.
Solution Approach 2:
The inlet cross-section area is changed as a variable parameter rather than being fixed. The movable elements enable continuous adjustment of the cross-section area from minimum to maximum positions, allowing the system to optimize the extraction rate according to demand while minimizing flow resistance when extraction is not required. This parameter variability enables the system to achieve both low energy losses and high productivity as needed.
4Productivity
If a fixed inlet orientation is used, then the structure is simple, but the extraction efficiency cannot be optimized for different operating conditions
Solution Approach 1:
The inlet orientation is made dynamic through the movable elements that can change their position and angle relative to the inlet axis. This dynamic orientation capability allows optimization of the inlet angle for different operating conditions and airflow patterns. The actuator controls these movements, enabling the inlet to adapt its orientation to maximize extraction efficiency under varying conditions, justifying the added complexity through improved productivity.
Solution Approach 2:
The inlet orientation angle is changed as a controllable parameter. The movable elements can adjust the angle at which the inlet cross-section presents to the flowing air, optimizing the extraction efficiency for different flight conditions, speeds, and bleed air demands. This parameter adjustment capability enables the system to maintain high extraction efficiency across a range of operating conditions, outweighing the complexity of the adjustment mechanism.
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 enables efficient and controlled extraction of bleed air with reduced flow resistance, allowing for optimal air management and utilization in aircraft engines, improving operational efficiency and reducing energy losses.
Implementation Method 1
a flow guide means for separating a boundary layer flow; the flow guide means has a rounded, essentially wedge-shaped nose which is directed into the boundary layer flow and is arranged below the inlet cross section, so that boundary layer flows are selectively separated and diverted in a bypass duct
Data Source
Figure 1
Figure 2A~2B
Figure 2C
AI summary
The invention relates to a device for extracting bleed air from flowing air at or in an aircraft engine, comprising a means (5) for selectively adjusting an inlet cross-section (A) for an opening (1) in or in the region of a wall (102) of the aircraft engine (100) with a flow guide (20) for a boundary layer flow (G), in particular a separation of the boundary layer flow (G). The invention also relates to an aircraft engine (100) with such a device.