59results about How to "Reduce viscous drag" patented technology

The invention is directed to an article with a liquid-impregnated surface, the surface having a matrix of features thereupon, spaced sufficiently close to stably contain a liquid therebetween or therewithin, and preferable also a thin film thereupon. The surface provides the article with advantageous non-wetting properties. Compared to previous non-wetting surfaces, which include a gas (e.g., air) entrained within surface textures, these liquid-impregnated surfaces are resistant to impalement and frost formation, and are therefore more robust.

The invention relates to the field of train operation safety, and discloses a train imitation fish scale anti-overturning structure to ensure the safety of train operation. Including: base, mounting hole, support frame, rotating shaft, scales, micro motor, control box and wind speed detection device; the base is provided with a mounting hole for fixing with the car body; one end of the base is provided with a support frame; The lower end of the frame is provided with a rotating shaft; the rotating frame is fixedly connected with the supporting frame; scales are fixed on the supporting frame; a wind direction detection device is arranged on the windward side of the scales; the micro motor is used to drive the rotation of the rotating shaft; the micro motor and the wind speed detection device are also Connect with the control box respectively; the control box is used to obtain the wind speed and wind direction angle during the train travel through the wind speed detection device, evaluate the risk level according to the wind speed and wind direction angle, and calculate the scale that minimizes the overturning moment when evaluating the risk Opening angle, and command the micro motor to drive the scales through the rotating shaft to reach the opening angle of the scales that minimizes the overturning moment.

A metamaterial has a magnetic permeability response at frequencies sufficient to generate a repulsive force between a fluid and a surface to which the metamaterial may be applied. The metamaterial may be nanofabricated such that an absolute value of the magnetic permeability of the metamaterial is substantially greater than an absolute value of an electric permittivity of the metamaterial. The metamaterial may generate a repulsive force between the surface and the fluid moving relative to the surface and thereby reduce viscous drag of the fluid on the surface. A method of reducing the viscous drag of the fluid moving past the surface includes producing relative motion between the surface and the fluid and generating the repulsive force between the surface and the fluid.

In certain embodiments, the invention relates to an electrochemical device having a liquid lubricant impregnated surface. At least a portion of the interior surface of the electrochemical device includes a portion that includes a plurality of solid features disposed therein. The plurality of solid features define a plurality of regions therebetween. A lubricant is disposed in the plurality of regions which retain the liquid lubricant in the plurality of regions during operation of the device. An electroactive phase comes in contact with at least the portion of the interior surface. The liquid lubricant impregnated surface introduces a slip at the surface when the electroactive phase flows along the surface. The electroactive phase may be a yield stress fluid.

The invention discloses a platform moon pool damping device which comprises a shock absorption cabin and a shake absorption cabin which are arranged on the transverse inner walls at the two ends of a moon pool and separated through a watertight separation board. Multiple rows of damping blocks distributed in a staggered manner are transversely arranged on the outer wall of the shock absorption cabin and the outer wall of the lower portion of the shake absorption cabin respectively. Multiple wave stop columns are arranged on the outer wall of the lower portion of the shake absorption cabin. Three separation boards are arranged in the shake absorption cabin from top to bottom. Multiple rows of vertical wave elimination blocks horizontally distributed in a staggered manner are transversely arranged on the upper sides and the lower sides of the separation boards and the inner wall of the shake absorption cabin bottom. The separation boards are provided with vertically-corresponding wedge blocks towards the outer end of the platform moon pool. Multiple rectangular openings are formed in the shock absorption cabin outer wall and a vertical wall board of the shock absorption cabin respectively. Multiple rows of horizontal wave elimination blocks vertically distributed in a staggered manner are transversely arranged on the inner walls of the two longitudinal ends and a vertical wall board of the moon pool. The shock absorption cabin and the shake absorption cabin can guarantee that a platform works safely and stably under different working conditions. The wave stop columns arranged on the outer wall of the lower portion of the shake absorption cabin can effectively resist incoming flow impact, the kinetic energy of waves is weakened, incoming flow is inducted to move towards the bottom of the moon pool, and formed vortexes in the moon pool are reduced.

A pump assembly includes a pump unit having a centrifugal pump and a variable pump supplying pressurized flow. A fuel control assembly receives flow from the pump unit and includes at least one metering valve and at least one throttling valve. A control for the variable pump receives first and second pressure signals indicative of a pressure differential across the throttling valve, or across the metering valve / throttling valve combination, for altering operation of the variable pump in response to the pressure differential.