There is disclosed a unidirectional liquid transport system. The system, or a liquid diode, has an array of elongate units. Each unit is defined by a surrounding fencing, and includes a region generally resembling a U-shaped micro-scale island with a proximal end on one side having an opening and a distal end on the opposite side thereof. A channel is defined between a lateral side of the island and an adjacent fencing thereof, and the channel is divergent from the proximal end towards the distal location on the opposite side thereof. The island includes a reentrant member configured to, upon contact with droplets of a liquid to be transported, initially arrest flow of the liquid and produce a pinning acting to allow building up of excess surface energy, and subsequently cause coalescence of the liquid thus converting the surface energy to kinetic energy for movement of the liquid; and surfaces of the units are fabricated on silicon wafer.

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.

A method and apparatus for generating a wave in a body of water may include altering a flow of water as it is urged through an inlet, contoured passage, and outlet. For example, a primary flow of water may be altered so that one or more secondary flows are created at angles to the direction of primary flow.

There is disclosed a unidirectional liquid transport system. The system, or a liquid diode, has an array of elongate units. Each unit is defined by a surrounding fencing, and includes a region generally resembling a U-shaped micro-scale island with a proximal end on one side having an opening and a distal end on the opposite side thereof. A channel is defined between a lateral side of the island and an adjacent fencing thereof, and the channel is divergent from the proximal end towards the distal location on the opposite side thereof. The island includes a reentrant member configured to, upon contact with droplets of a liquid to be transported, initially arrest flow of the liquid and produce a pinning acting to allow building up of excess surface energy, and subsequently cause coalescence of the liquid thus converting the surface energy to kinetic energy for movement of the liquid; and surfaces of the units are fabricated on silicon wafer.

A fluid control film is provided that includes fluid control channels extending along a channel longitudinal axis. Each of the fluid control channels has a surface and is configured to allow capillary movement of liquid in the channels. The fluid control film further includes a hydrophilic surface treatment covalently bonded to at least a portion of the surface of the fluid control channels. The fluid control film exhibits a capillary rise percent recovery of at least ten percent. Typically, the hydrophilic surface treatment includes functional groups selected from a non-zwitterionic sulfonate, a non-zwitterionic carboxylate, a zwitterionic sulfonate, a zwitterionic carboxylate, a zwitterionic phosphate, a zwitterionic phosphonic acid, and/or a zwitterionic phosphonate. A process for forming a fluid control film is also provided. Further, a process for cleaning a structured surface is provided, including providing a structured surface and a hydrophilic surface treatment covalently bonded to at least a portion of the structured surface, and soiling the structured surface with a material. The process also includes removing the material by at least one of submerging the structured surface in an aqueous fluid, rinsing the structured surface with an aqueous fluid, condensing an aqueous fluid on the structure surface, or wiping the structured surface with a cleaning implement.

Various embodiments of an airfoil and machines with airfoils are disclosed. The airfoils include a thicker leading airfoil portion and a thinner trailing airfoil portion. In one embodiment, the leading airfoil portion is formed by bending a body of the airfoil back toward itself. In another embodiment, the leading airfoil portion has a solid geometry and includes two elliptic surfaces. To prevent detachment of airflow, the leading airfoil portion includes at least two arc portions or surfaces that act to direct the airflow down to the trailing airfoil portion in a manner that stabilizes vortexes that may form in the region of changing thickness.

The curved flow channel with built-in lattice structure provided by the present application is configured with the lattice structure disposed at the outer inside wall of the curved section away from a center of curvature of the curved section. Through geometry and distribution design of the lattice structure, flow rate and flow direction of fluid impacting the lattice structure can be altered, which achieves the purpose of flow rate redistribution in the curved flow channel and produces a downstream flow field with uniform distribution.

A method of applying a riblet structure coating on the internal surface of a pipe includes coating the internal surface of a pipe with a resin layer and applying a cavity mold having a reverse riblet pattern structure to the coated internal surface of the pipe. A flexible air bag is inserted into the interior of the pipe and charged with air to hold the mold against the coated internal surface of the pipe. The air bag may be charged with air for a sufficient amount of time to allow the coating to cure in the riblet shape of the mold. Afterwards, the air bag and the mold are removed from the pipe to yield a pipe coated with an internal riblet structure.

The present invention relates to structured, gas-holding surfaces for improving the friction-reducing properties of gas layers held under a liquid and for the simultaneous suppression of turbulence. The present invention furthermore relates to a device comprising this structured, gas-holding surface and to the use of this structured, gas-holding surface.

This disclosure relates to a method and resulting apparatus of applying a riblet sheet comprising a riblet film layer and a riblet liner layer on an airfoil surface. The method comprises applying the riblet film layer of the riblet sheet over the airfoil surface, peeling back at least a portion of the riblet liner layer from the riblet film layer to expose a portion of the riblet film layer, applying a attaching hardware or a non-textured surface film over at least a portion the riblet film layer portion; and applying the peeled back portion of the riblet liner layer over a portion of the attaching hardware.