Microstructured Aerodynamic Surface for Low-Drag Aircraft Walkways
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Solution Overview
Problem
Current over-wing walkways on aircraft suffer from high aerodynamic drag due to crushed minerals used for friction, which are messy to apply and inefficient, and riblet surfaces lose friction when contaminated, while also needing clear markings for safety.
Innovation Solution
Aerodynamic articles with microstructured surfaces featuring parallel primary and secondary ridges that provide oleophilic properties, reducing drag and maintaining high friction under dry and contaminated conditions, combined with embedded visual markings for safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If crushed minerals are used for over-wing walkways, then friction is improved, but aerodynamic drag increases and application becomes messy
Solution Approach 1:
The patent employs a porous polymer material with controlled pore structure to provide friction for over-wing walkways. The porous nature allows the material to maintain high friction coefficients while being aerodynamically compatible, eliminating the need for crushed minerals that create turbulence and drag.
Solution Approach 2:
The invention changes the physical and chemical parameters of the friction surface by using a polymer material with specific glass transition temperature, hardness, and pore structure. This allows optimization of both friction properties and aerodynamic performance simultaneously, rather than relying on traditional mineral-based solutions.
2Object-generated harmful factors
If riblet surfaces are used for over-wing walkways, then aerodynamic drag is reduced, but friction is lost when contaminated with liquids
Solution Approach 1:
The porous polymer material provides friction that is not dependent on surface riblet structures. The three-dimensional pore network maintains mechanical interlocking with shoe soles even when liquid contaminants are present, unlike riblet surfaces where liquids can fill the grooves and eliminate friction.
Solution Approach 2:
The invention uses a composite approach by combining polymer material with specific pore structure and surface properties to achieve both aerodynamic compatibility and reliable friction. This composite structure integrates the benefits of smooth aerodynamic surfaces with the friction-providing characteristics of textured surfaces.
3Reliability
If crushed minerals are painted on wings, then friction is provided, but application becomes messy and time-consuming
Solution Approach 1:
The patent employs a flexible polymer film that can be applied as a continuous sheet to the wing surface. This eliminates the messy painting process required for crushed minerals, as the pre-formed film simply needs to be positioned and adhered to the surface, significantly reducing application time and mess.
Solution Approach 2:
The friction-providing polymer material is pre-formed into a film with the desired properties before application. This preliminary preparation of the material allows for clean, rapid installation without the need for on-site mixing or painting operations that characterize traditional mineral application methods.
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 microstructured surfaces significantly reduce drag and maintain high friction on aircraft surfaces, even when contaminated, while providing clear visual markings for pedestrian safety.
Implementation Method 1
By disrupting large scale vortices in these turbulent regions near the surface in the boundary layer, riblets can significantly reduce drag on aircraft wings and other surfaces.
Implementation Method 2
a microstructured surface on the aerodynamic body, the microstructured surface being an oleophilic surface and comprising: a plurality of parallel, primary ridges defining major capillary channels; and a plurality of parallel, secondary ridges having a height less than that of the primary ridges and extending between and generally parallel to the primary ridges, each secondary ridge at least partially defining two or more minor capillary channels within a respective major capillary channel
Data Source
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AI summary
Provided are aerodynamic articles and related methods that use an aerodynamic body with a microstructured surface thereon. The microstructured surface has a plurality of parallel primary ridges defining major capillary channels, and optionally a plurality of parallel secondary ridges having a height less than that of the primary ridges and extending between and generally parallel to the primary ridges. The optional secondary ridges at least partially define two or more minor capillary channels within each major capillary channel. The aerodynamic surface provides reduced drag and is capable providing a high degree of friction against shoe surfaces under oil and water contaminated conditions.