Pylon Profile Boundary Layer Suction for Wake Turbulence
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Solution Overview
Problem
The existing pylon designs generate a wake with speed and mass flow deficiencies, leading to turbulence and increased noise and vibrations, which complicate aircraft design and increase fatigue, due to the boundary layer thickness increasing downstream, causing inefficiencies in propeller performance.
Innovation Solution
A streamlined pylon profile with a suction device, known as a 'scoop inlet,' draws air from the boundary layer and discharges it near the trailing edge, using a discharge nozzle with acceleration means to compensate for pressure deficits, eliminating the need for complex piping systems and external air sources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If air is blown from a high-pressure source close to the trailing edge of the pylon profile, then the speed deficit is reduced, but the system complexity and weight increase due to piping requirements
Solution Approach 1:
The invention extracts air from the boundary layer itself using a suction device located at the trailing edge, eliminating the need for external high-pressure air sources and complex piping systems. The suction device directly removes slow-moving boundary layer air without requiring connections to engine compressors or other external sources.
Solution Approach 2:
The pylon profile serves its own boundary layer management needs by incorporating the suction device directly into its structure. The profile extracts and recirculates its own boundary layer air through the suction device and discharge nozzle, making the system self-sufficient without external air sources or complex interconnections.
2Object-affected harmful factors
If air is drawn from the engine compressor to eliminate speed deficit, then the wake turbulence is reduced, but the engine design becomes more complicated
Solution Approach 1:
The invention extracts air directly from the pylon's own boundary layer rather than drawing from the engine compressor, thereby eliminating the need to modify engine design or add air extraction systems to the propulsion components.
Solution Approach 2:
The boundary layer control function is separated from the engine system and integrated into the pylon structure itself. The suction device, discharge nozzle, and air intake are positioned on the pylon profile, creating an independent boundary layer management system that does not interfere with engine design.
3Object-affected harmful factors
If a piping system is added to convey air from compressor to trailing edge, then the speed deficit is compensated, but the aircraft weight increases
Solution Approach 1:
The invention eliminates the piping system entirely by extracting air directly from the boundary layer at the trailing edge location where it is needed, removing the weight penalty of pipes, connectors, and associated hardware.
Solution Approach 2:
The pylon profile manages its own boundary layer using locally-sourced air from its own boundary layer, eliminating the need for external air supply systems and their associated weight penalties.
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
This solution reduces speed deficits and turbulences, minimizing noise and vibrations, while simplifying aircraft design and reducing weight by reusing suctioned air and requiring minimal energy for acceleration, thus enhancing propeller interactions and overall aircraft performance.
Implementation Method 1
a device for suctioning air («scoop inlet» in English terminology) from a boundary layer which is formed on this profile
Implementation Method 2
the discharge of this suctioned air close to the trailing edge of the profile also contributes to reducing the speed deficit
Implementation Method 3
the discharge nozzle is equipped with means for accelerating the discharged air, such as ejectors
Data Source
AI summary
A streamlined profile reducing the speed deficit in a wake, a pylon with such a profile, a propulsion assembly including such a pylon and an aircraft including this assembly. The profile has a device for suction of air from the boundary layer formed on this profile. This suctioned air is discharged with the aid of a nozzle the outlet of which is situated close to the trailing edge of the profile. Suction of the air and discharge thereof contribute to reducing the speed deficit downstream from the profile and therefore to reducing the turbulences in this zone.