In an embodiment, an article comprises a plurality of structural units, wherein each structural unit comprises a first portion; a second portion; wherein the second portion contacts the first portion; and a third portion; wherein the third portion is in communication with the first portion and the second portion and is more compressible than the first portion and the second portion; where the first portion has a first value of a property and where the second portion has a second value of the same property, such that the first value acts as a restraining or enhancing force on the second value; wherein the first portion comprises a first metal and wherein the second portion comprises a second metal that is different from the first metal.

A fairing, in the form of a contoured restriction, submerged on a fluid channel surface of a fluid channel through which liquid flows, re-distributes velocity fields and flow geometries upstream and in some embodiments downstream of a discontinuity, thereby preventing flow separation, reducing cavitation potential and increasing flow capacity. Such discontinuities include, but are not limited to: joints, for example elbow joints, T-joints and Y-joints; valve-trims; entrance regions to centrifugal pumps; and entrance regions to rotary valves, steps, reductions, expansions and ledges. The fairing may be fitted into the channel or integrally fabricated with the channel.

A fairing, in the form of a contoured restriction, submerged on a fluid channel surface of a fluid channel through which liquid flows, re-distributes velocity fields and flow geometries upstream and in some embodiments downstream of a discontinuity, thereby preventing flow separation, reducing cavitation potential and increasing flow capacity. Such discontinuities include, but are not limited to: joints, for example elbow joints, T-joints and Y-joints; valve-trims ; entrance regions to centrifugal pumps; and entrance regions to rotary valves, steps, reductions, expansions and ledges. The fairing may be fitted into the channel or integrally fabricated with the channel.

The disclosure provides an airflow regulation and control apparatus. A ventilation hole (11) is formed in a windshield (1) in a penetrating manner; a guide rail gate disc (2) is mounted on the windshield (1); the guide rail gate disc (2) is lifted by means of power provided by a lifting wing (3) disposed thereon, and the height of the guide rail gate disc (2) when moving upwards exceed the height of an upper edge of a main body portion of the windshield (1); when wind strength is low, the guide rail gate disc (2) is located at a lower portion under the action of gravity and shields the ventilation hole (11); when the wind strength is increased, the lifting wing (3) is blown by airflow to generate upwards lifting force, and drives the guide rail gate disc (2) to upwards move so as to shield an upper portion of the windshield (1) and block the airflow; and after part of the airflow blows to the windshield (1) through the ventilation hole (11), the excess airflow flows through the upper portion and both sides of a whole board surface defined by the windshield (1) and the guide rail gate disc (2). By blocking part of the airflow and reducing the airflow blowing to the rear of the windshield (1), more airflow is transferred to other positions, the airflow is better distributed, and the airflow meets the requirements of various components for the cooling airflow, so that an effect of reducing energy consumption is achieved.

A material for use in interacting with a flow is provided. The material comprises an interface surface adapted to move in response to a pressure associated with at least one wave in a flow exerted on the interface surface; and a subsurface feature extending from the interface surface, the subsurface feature comprising a phononic crystal or locally resonant metamaterial adapted to receive the at least one wave having the at least one frequency based upon the pressure from the flow via the interface surface and alter a phase of the at least one wave. The subsurface material comprises a lattice-structured material comprising a plurality of structural elements and a plurality of voids, and the interface surface is adapted to vibrate at a frequency, phase, and amplitude in response to the altered phase of the at least one wave. A method for interacting with a flow is also provided.

Structural subsurface materials and subsurface structures adapted for interacting with a flow are provided. In one example, a structural subsurface material or subsurface structure is provided for use in interacting with a fluid or solid flow. The structural subsurface material comprises a flow interface surface adapted to be disposed adjacent a flow and a subsurface feature comprising a structural material. The subsurface feature extends away from the flow interface surface. The subsurface feature alters an effective structural compliance of the flow interface surface relative to the flow such that the flow experiences an alteration in surface skin-friction drag and/or in kinetic energy in a turbulent flow. In other implementations, methods of controlling a flow with a structural subsurface material or a subsurface structure are provided. Further, methods of designing structural subsurface materials and subsurface structures for interacting with a flow are also provided.

A phononic material and a method of using a phononic material for use in interacting with a fluid or solid flow are provided. The phononic material includes an interface surface and a subsurface feature. The interface surface is adapted to move in response to a pressure associated with at least one wave in a flow exerted on the interface surface. The subsurface feature extends from the interface surface. The subsurface feature comprises a phononic crystal or locally resonant metamaterial adapted to receive the at least one wave having the at least one frequency based upon the pressure from the flow via the interface surface and alter the phase of the at least one wave. The interface surface is adapted to vibrate at a frequency, phase and amplitude in response to the manipulated/altered phase of the at least one wave.

A phononic material and a method of using a phononic material for use in interacting with a fluid or solid flow are provided. The phononic material includes an interface surface and a subsurface feature. The interface surface is adapted to move in response to a pressure, and/or velocity gradients, associated with complex motion of a turbulent flow exhibiting a polarity of frequencies exerted on the interface surface. The subsurface feature extends from the interface surface. The subsurface feature comprises a phononic crystal or locally resonant metamaterial adapted to receive the pressure, and/or velocity gradients, from the turbulent flow via the interface surface and alter the phase and amplitude of a polarity of frequency components of the turbulent flow in order to reduce or increase the kinetic energy of the turbulent flow. The interface surface is adapted to vibrate at a polarity of frequencies, phases and amplitudes in response to the frequency, phase and amplitude of at least one component of the turbulent flow.

A phononic material includes an interface surface and a subsurface feature mechanically connected to the interface surface. When a hypersonic flow having at least one instability flows past the interface surface, the interface surface vibrates in response to one or more frequency components of the pressure. The interface surface couples each frequency component into the subsurface feature, which at least partially reflects and phase-shifts each frequency component to generate a corresponding phase-shifted frequency component. The interface surface vibrates in response to the phase-shifted frequency component, thereby coupling the phase-shifted frequency component back into the hypersonic flow. The phase-shifted frequency component interferes with said each frequency component within the hypersonic flow. The subsurface feature may perform phase-shifting such that the phase-shifted frequency component destructively interferes with said each frequency component, thereby reducing the at least one instability.

The disclosure provides an airflow regulation and control apparatus. A ventilation hole is formed in a windshield in a penetrating manner; a rectangular plate is mounted on the windshield; the rectangular plate is lifted by means of power provided by a lifting wing disposed thereon, and the height of the rectangular plate when moving upwards exceed the height of an upper edge of a main body portion of the windshield; when wind strength is low, the rectangular plate is located at a lower portion under the action of gravity and shields the ventilation hole; when the wind strength is increased, the lifting wing is blown by an airflow to generate upwards lifting force, and drives the rectangular plate to moved upwardly so as to shield an opening in an upper portion of the windshield and block the airflow.