Aircraft Wing Trailing Edge Angles for Jet Noise Reduction
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Solution Overview
Problem
Existing aircraft designs with high bypass ratio jet engines face significant installation noise due to the interaction between the jet engine's turbulent flow and the wing, which current noise reduction methods, such as flaps with saw tooth trailing edges or vortex generators, only marginally address.
Innovation Solution
The design incorporates an aircraft wing with specific trailing edge and rear longitudinal edge angles that intercept the jet engine's flow, optimizing the angle ranges between 5° and 65° or 115° and 175° to reduce installation noise, and ensures a ratio of jet engine axis to wing distance less than 2, with a gas flow velocity between 0.3 and 0.9 Mach, and a Strouhal number below 1.5.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the jet engine diameter is increased to reduce noise, then the fuel consumption decreases, but the installation noise increases due to closer proximity to the wing
Solution Approach 1:
The patent applies local quality by modifying specific portions of the wing trailing edge (first portion with specific angle ranges) rather than the entire wing structure. This localized modification allows the wing to interact favorably with the jet flow in the critical interaction zone while maintaining the overall wing design and the benefits of large-diameter high bypass ratio engines.
Solution Approach 2:
The patent changes the geometric parameter of the trailing edge angle to specific ranges (5°-65° or 115°-175°) to optimize the interaction between jet flow and wing. This parameter modification reduces the strength of jet-wing interaction noise while preserving the engine configuration that provides low fuel consumption.
2Use of energy by moving object
If the distance between the jet engine and wing is reduced to accommodate large diameter engines, then the fuel efficiency improves, but the interaction noise between jet and wing increases
Solution Approach 1:
The invention applies local quality by modifying specific portions of the wing trailing edge (first portion with specific angle ranges) rather than the entire wing structure. This localized modification allows the wing to interact favorably with the jet flow in the critical interaction zone while maintaining the overall wing design and the benefits of large-diameter high bypass ratio engines.
Solution Approach 2:
The patent changes the geometric parameter of the trailing edge angle to specific ranges (5°-65° or 115°-175°) to optimize the interaction between jet flow and wing. This parameter modification reduces the strength of jet-wing interaction noise while preserving the engine configuration that provides low fuel consumption.
3Object-generated harmful factors
If conventional noise reduction devices (saw tooth trailing edges, vortex generators) are added to the wing, then some noise reduction is achieved, but the device complexity increases and the noise reduction effect is marginal
Solution Approach 1:
The patent changes the geometric parameter of the trailing edge angle to specific ranges (5°-65° or 115°-175°) to optimize the interaction between jet flow and wing. This parameter modification reduces the strength of jet-wing interaction noise while preserving the engine configuration that provides low fuel consumption.
Solution Approach 2:
Instead of adding complex devices to modify the jet flow or trailing edge, the invention inverts the approach by carefully designing the trailing edge geometry itself with specific angle ranges. This inverted approach uses the natural wing structure as the noise control element rather than adding separate modification devices.
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 configuration significantly reduces installation noise by up to 8 dB, with a broader azimuthal noise reduction range, and effectively manages the interaction between the jet engine and wing, improving sound power levels and directivity.
Implementation Method 1
the turbulent flow of the jet from the engine and the solid surface presented by the wing
Implementation Method 2
at least one jet engine with high bypass ratio attached to said wing, suitable for emitting a jet intercepted by a first portion of the trailing edge of said wing
Data Source
AI summary
In the field of aeronautics, there is disclosed an aircraft with reduced installation noise and specifically an aircraft wing and jet engine system including an aircraft wing and at least one jet engine with high bypass ratio attached to the wing, suitable for emitting a jet intercepted by a first portion of the trailing edge of the wing. The range formed by the set of angles with orientation α defined by a vector following the direction of the jet and by a vector following the tangent at a point of the first portion of the trailing edge and oriented towards the wing tip of the wing, is included within a range of angles selected from the range delimited by 5° and 65°, and the range delimited by 115° and 175°.