A vacuum pump includes a plurality of exhaust stages provided between an inlet port and an exhaust port so as to function as means for exhausting gas molecules, and a number of blades provided between the inlet port and an uppermost exhaust stage of the plurality of exhaust stages so as to rotate together with a rotary blade that constitutes the uppermost exhaust stage as a particle transport stage for transporting particles in an exhaust direction of the gas molecules, the number being smaller than the number of rotary blades that constitutes the uppermost exhaust stage.

The present disclosure relates to devices (350) for reducing vibrations in wind turbines (10) and to methods (450) for using the devices (350) and mitigating wind turbine vibrations. More particularly, the present disclosure relates to devices (350) for reducing vortex induced vibrations and stall induced vibrations when the wind turbine (10) is parked, especially during wind turbine installation and/or maintenance, and to ways in which the devices (350) can be used, e.g. for installing them on wind turbine blades (22) or once they are already installed thereon. A vibration mitigating device (350) for mitigating vibrations of a parked wind turbine (10) is provided. The device (350) is configured to be arranged with a wind turbine blade (22). The device (350) comprises one or more air flow modifying elements (330). At least one of the air flow modifying elements (330) is configured to change between a retracted configuration (370) and an extended configuration (375).

The present disclosure relates to devices (300) for wind turbine blades (22) and methods (400) for reducing vibrations in wind turbines (10). More particularly, the present disclosure relates to devices (300) for mitigating vortex induced vibrations and stall induced vibrations, wind turbine blades (22) comprising such devices (300), and methods (400) for reducing wind turbine vibrations when the wind turbine (10) is parked, especially during wind turbine installation and/or maintenance. A device (300) is configured to be arranged around a wind turbine blade (22) and comprises three or more air flow modifying elements (305) comprising a concave outer surface (323) configured to face away from a wind turbine blade (22). The device further comprises a supporting structure (310) configured to support the plurality of air flow modifying elements (305). An angular distance (307) between adjacent air flow modifying elements (305) in cross-section is substantially constant.

The invention is directed to embodiments of wind turbine arrangements. One wind turbine arrangement includes an inflatable component disposed within a hollow section of a wind turbine blade, wherein the inflatable component is a platform usable during service and/or installation of a wind turbine module, wherein the inflatable component includes an inflation structure with an air tight shell, wherein the air tight shell includes an inner shell and an outer shell surrounding the inner shell, and wherein the outer shell includes a material that protects against puncture of the inner shell. Another wind turbine arrangement includes a wind turbine blade; an inflatable platform positioned in the wind turbine blade; and an inflatable outer pressure ring that surrounds the platform, wherein the outer pressure ring, when inflated, fixes the platform in the wind turbine blade by generating a normal friction force between the platform and the wind turbine blade.

An accelerated and/or redirected flow arrangement, optimally serving as a wildlife and/or debris excluder (WDE), is used in combination with a turbine-like device having an inlet end and an outlet end for fluid flowing therethrough, e.g., a hydro-turbine. The arrangement includes at least a forward part designed to be placed in front of a fluid inlet of a turbine-like device and configured to produce at least one of the following effects on the fluid: (a) imparting a re-direction of the fluid; and/or (b) accelerating the flow velocity of the fluid, as it flows through the forward part. Turbine-like devices having both a forward part and a rearward part of flow arrangement are disclosed, as well as a method of enhancing turbine performance.

A family of dual-winglet rotor blades are designed to dissipate the low energy flow in the wake of a turbine rotor. In some embodiments a dual-winglet having a first winglet transitioning from the lift surface of a rotor blade and a second winglet transitioning from the pressure surface of the rotor blade creates two distinct streams in the wake of the rotor. In one embodiment the first winglet curving away from the lift surface turns the lift force toward the center of the rotor plane while a second, smaller, winglet curving away from the pressure surface of the rotor blade turns the lift force away from the center of the rotor plane. In other embodiments winglets create a virtual shroud that expands the wake to dissipate the low-energy flow in the turbine wake. In another embodiment a dual winglet combines the aforementioned mixing effect with the wake expansion effect.

The present disclosure relates to devices (300) for wind turbine blades (22) and methods (400) for reducing vibrations in wind turbines (10). More particularly, the present disclosure relates to devices (300) for mitigating vortex induced vibrations and stall induced vibrations, wind turbine blades (22) comprising such devices (300), and methods (400) for reducing wind turbine vibrations when the wind turbine (10) is parked, especially during wind turbine installation and/or maintenance. A device (300) is configured to be arranged around a wind turbine blade (22) and comprises three or more air flow modifying elements (305) comprising a concave outer surface (323) configured to face away from a wind turbine blade (22). The device further comprises a supporting structure (310) configured to support the plurality of air flow modifying elements (305). An angular distance (307) between adjacent air flow modifying elements (305) in cross-section is substantially constant.

Extracorporeal circuit devices can be used for on-pump open-heart surgery to support surgical procedures such as coronary artery bypass grafting. In some cases, a centrifugal pump is used as part of an extracorporeal circuit. Centrifugal pump heads are described herein that induce flow on two sides of an impeller plate, and that can be conveniently mechanically assembled.

Wind turbine systems and methods are disclosed herein. A representative system includes a wind turbine blade having an inner region that has an internal load-bearing truss structure, and an outer region that has an internal, non-truss, load-bearing structure. In particular embodiments, the truss structure can include a triangular arrangement of spars, and/or can include truss attachment members that connect components of the truss without the use of holes in the spars. Spars can be produced from a plurality of pultruded composite members laminated together in longitudinally extending portions. The longitudinally extending portions can be connected at joints that interleave projections and recesses of each of the spar portions. The blades can include fan-shaped transitions at a hub attachment portion, formed by laminated layers and/or a combination of laminated layers and transition plates.

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.