The disclosure relates to a damping arrangement for vibration damping of an element in an optical system, for example in a microlithographic projection exposure apparatus. A damping arrangement according to the disclosure has an element, a fluid located in a cavity, and at least one channel connected to the cavity. A vibration of the element causes vibration energy of the element to be dissipated by partial displacement of the fluid from the cavity into the at least one channel.

A frequency-tunable vibration damper includes a first container having rigid wall regions and compliant wall regions. A second container is coupled to the first container such that a wall region of the second container includes one of the compliant wall regions. A fluid fills the first container and a gas fills the second container. A flow restrictor is included in the second container and is spaced-apart from the one of the compliant wall regions included with the second container.

Aspects of the present disclosure relates to disruptive coupling systems and methods, and apparatus thereof, for subsea systems. The subsea systems may be subsea oil and gas systems. In one implementation, a subsea system includes a subsea component disposed in seawater, and a disruptive coupling device coupled to the subsea structure and/or surrounding fluid.

A shock absorber includes a cylinder-side member having an inner cylinder, a piston-side member having a piston and a piston rod that move relative to the inner cylinder, and a phase correction communication passage. The phase correction communication passage is provided between a bottom-side oil chamber, which is one side chamber, and a rod-side oil chamber, which is the other side chamber. That is, the phase correction communication passage is provided in the inner cylinder which is the cylinder-side member and communicates the bottom-side oil chamber and rod-side chamber with each other. By having a spiral conduit that advances in the axial direction while spiraling (orbiting) multiple times at the same diameter, the phase correction communication passage is configured as a second damping mechanism which generates a force (an axial force) that advances the phase of the damping force.

The present invention relates to a damper module adapted to be secured to a wind turbine tower section, the damper module comprising at least one liquid damper secured to a frame structure, wherein each liquid damper comprises a container comprising an interior volume containing an amount of liquid, wherein the amount of liquid in the interior volume of the container sets a natural frequency of the liquid damper, and wherein the frame structure comprises an interface arrangement configured for, in cooperation with a damper module suspension arrangement in a tower section, securing the damper module to said tower section, and a liquid damper fastening arrangement configured for securing said at least one liquid damper to the frame structure. The present invention further relates to a liquid damper and a tower section having at least one damper module secured thereto.

A method of isolating vibrations between vibrating bodies includes determining a pressure differential between a first fluid chamber and a second fluid chamber of a liquid inertia vibration eliminator (LIVE) unit, and selectively injecting fluid into or withdrawing fluid from the LIVE unit based on the pressure differential. A system for isolating vibrations between bodies includes a vibration isolator including fluid, a fluid regulator valve in fluid communication with the vibration isolator to selectively flow fluid through the vibration isolator, a pressurized fluid source in fluid communication with the fluid regulator to supply fluid to the fluid regulator, a controller in signal communication with the fluid regulator to control fluid flow between the fluid regulation valve and the vibration isolator, and at least one sensor in signal communication with the controller.

A tunable vibration isolator with active tuning elements having a housing, fluid chamber, and at least one tuning port. A piston is resiliently disposed within the housing. A vibration isolation fluid is disposed within the fluid chambers and the tuning ports. The tunable vibration isolator may employ either a solid tuning mass approach or a liquid tuning mass approach. The active vibration elements are preferably solid-state actuators.

A compound helicopter includes a fuselage including a fuselage airframe, a translational thrust system coupled to the fuselage airframe and a pylon assembly subject to vibration. The pylon assembly includes a transmission and a rotor system having a main rotor assembly. The compound helicopter also includes a main rotor vibration isolation system including a plurality of augmented liquid inertia vibration eliminator units each having an isolation frequency and each coupled between the fuselage airframe and the pylon assembly to reduce transmission of the pylon assembly vibration to the fuselage airframe at the isolation frequency. Each augmented liquid inertia vibration eliminator unit includes at least one active tuning element movable to tune the isolation frequency thereof.

Aspects of the present disclosure relates to disruptive coupling systems and methods, and apparatus thereof, for subsea systems. The subsea systems may be subsea oil and gas systems. In one implementation, a subsea system includes a subsea component disposed in seawater, and a disruptive coupling device coupled to the subsea structure and/or surrounding fluid.

A system for damping vibration of a tower structure at a selected one or more natural frequencies of the tower structure. The system includes a tank assembly with one or more tanks, and a fluid positioned in the tank to a preselected depth above a floor. The tank includes wall(s) defining an average travelling distance of a wave through the fluid initiated by the vibration of the tower structure at the natural frequency. The system includes one or more inserts located on the floor in the tank for damping movement of the fluid. The preselected depth and the average travelling distance are selected so that the fluid is movable at the selected natural frequency and out of phase with the vibration of the tower structure, to dampen the vibration of the tower structure at the selected natural frequency.