Johns Hopkins University

Stefan Szyniszewski

James Kevin Guest

Timothy P Weihs

Kevin J Hemker

Stephen Ryan

The present invention is directed to three dimensional (3D) woven lattices for drag and turbulence reduction. 3D woven lattice material can serve as a surface layer that regularizes the flow around a bluff body with beneficial effects on: 1) drag reduction, 2) decrease in turbulence intensity, 3) attenuation of flow-induced vibrations, and 4) aerodynamic noise cancellation. 3-D woven lattice architectures allows for passive flow control (without the need for external energy supply) around bluff bodies with restricted geometry/shape due to their functional requirements such as wind turbine towers, cargo trucks, train cars, etc. The woven material can be easily shaped to fit on various geometries and incorporated in existing manufacturing processes (from composites to metallic plates). Metallic foam and randomly porous materials have been identified in the literature as a promising solution for passive flow control over bluff bodies.

Three dimensional woven lattices for drag reduction and turbulence reduction

The present invention is directed to three dimensional weaves composed of wires or yarns that offer the potential for damping not achievable with solid materials, including high temperature damping. Three damping mechanisms have been identified: (1) Internal material damping, (2) Frictional energy dissipation (Coulomb damping), and (3) inertial damping (tuned mass damping). These three damping mechanisms can be optimized by modifying the wire material chemistries (metals, ceramics, polymers, etc.), wire sizes, wire shapes, wire coatings, wire bonding, and wire architecture (by removing certain wires). These have the effect of modifying the lattice and wire stiffnesses, masses, coefficients of friction, and internal material damping. Different materials can be used at different locations in the woven lattice. These design variables can also be modified to tailor mechanical stiffness and strength of the lattice, in addition to damping.

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Guildford, United Kingdom

Stefan Szyniszewski