Traversing Jet Actuator for Aircraft Flap Noise and Wake Reduction
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Solution Overview
Problem
Current methods for reducing noise and trailing vortices from aircraft flight control surfaces, such as blowing jets, require significant engine bleed, leading to increased weight and decreased efficiency, and result in airport congestion due to required separation distances for vortex dissipation.
Innovation Solution
Installation of a noise-reducing, wake-alleviating device within wing flap elements, featuring a traversing jet actuator and air-ejecting slot-shaped openings that produce small, fast-moving air jets to destabilize trailing vortices, reducing noise and vortex intensity with lower fluidic requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If blowing jets are used to reduce flap noise and trailing vortices, then noise and vortex intensity are reduced, but engine bleed requirement increases leading to increased weight and decreased efficiency
Solution Approach 1:
The patent divides the continuous blowing jet into multiple discrete pulsed jets that are ejected sequentially from the flap element. This segmentation allows the system to achieve vortex disruption with smaller, intermittent fluid injections rather than continuous large-scale blowing, thereby reducing engine bleed requirements and engine weight.
Solution Approach 2:
The patent employs periodic pulsed jets that are ejected at specific intervals during flap deployment. This periodic action creates time-varying flow structures that effectively disrupt trailing vortices and reduce flap noise while using significantly less fluid compared to continuous blowing systems, thus reducing engine bleed requirements and associated weight.
2Object-affected harmful factors
If blowing jets are used to reduce flap noise and trailing vortices, then noise and vortex intensity are reduced, but device complexity and fluidic requirements increase
Solution Approach 1:
The patent segments the fluid injection into multiple small pulsed jets rather than one large continuous jet. This segmentation enables effective vortex control with much smaller total fluid quantities, as the pulsed nature creates more efficient flow structures that disrupt vortices without requiring large volumes of fluid.
Solution Approach 2:
The patent applies partial action by using pulsed jets that are active only during specific phases of vortex formation and development. This approach uses fluid injection only when and where needed to maximize vortex disruption efficiency, rather than continuous fluid injection, thereby reducing overall fluidic requirements.
3Object-affected harmful factors
If engine bleed is increased to power blowing jets, then noise reduction is improved, but engine efficiency is degraded
Solution Approach 1:
The patent uses periodic pulsed jets that are activated only during approach and landing phases when flap noise is most problematic. This time-dependent activation ensures engine bleed is used only when necessary for noise reduction, minimizing the impact on engine efficiency during other flight phases.
Solution Approach 2:
The patent applies partial action by using small quantities of engine bleed air in pulsed form only during specific flight conditions (approach and landing). This selective, limited use of engine bleed air achieves noise reduction during critical phases without significantly degrading overall engine efficiency across all flight operations.
4Reliability
If separation distances are increased to allow vortex dissipation, then flight safety is improved, but airport productivity decreases
Solution Approach 1:
The patent converts the harmful trailing vortices into beneficial dispersed flow structures through pulsed jet injection. By actively disrupting and dissipating vortices, the system transforms a safety hazard into a controlled flow pattern, allowing reduced separation distances while maintaining flight safety.
Solution Approach 2:
The patent applies preliminary action by actively disrupting and dissipating trailing vortices before they can grow to hazardous levels. The pulsed jets are timed to interfere with vortex formation and development early in the process, preventing severe vortex encounters and enabling safer, closer aircraft spacing.
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 effectively reduces airplane noise and vortex intensity, allowing for closer aircraft separation distances, alleviating airport congestion and improving engine efficiency by using a fraction of the input required by traditional blowing systems.
Implementation Method 1
The actuation mechanism produces sets of small and fast-moving air jets which traverse the openings in a streamwise direction
Data Source
AI summary
Systems and methods for reducing the trailing vortices and lowering the noise produced by the side edges of aircraft flight control surfaces, tips of wings and winglets, and tips of rotor blades. A noise-reducing, wake-alleviating device is disclosed which incorporates an actuator and one or more air-ejecting slot-shaped openings coupled to that actuator and located on the upper and/or lower surfaces and/or the side edges of an aircraft flight control surface or the tip of a wing, winglet or blade. The actuation mechanism produces sets of small and fast-moving air jets that traverse the openings in the general streamwise direction. The actuation destabilizes the flap vortex structure, resulting in reduced intensity of trailing vortices and lower airplane noise.