Vibration Damping for Wind Turbine Noise Control

Nonlinear energy sinks (NESs) have been widely applied as passive control units in the field of vibration control. In this study, a grounded combined-stiffness NES is proposed, which consists linear stiffness and cubic stiffness. The suppression performance model under different excitations investigated. First, slow-varying equations system are derived using complexification-averaging method, followed by derivation amplitude-frequency response equation. Next, influence parameters on reduction harmonic impulsive analyzed. Finally, comparative analysis conducted NES, after parameter optimization Grey Wolf Optimizer (GWO) random excitation. results indicate that introducing into can significantly enhance system's performance. However, compared to dissipation primary more sensitive variations

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Mitigating vibrations of a wind turbine when it is not connected to the grid to prevent damage. The method involves using stored energy to reorient the turbine blades when conditions are unfavorable for vibration buildup. Sensors detect wind direction, blade pitch, and vibration. If wind misalignment, high wind speed, or high vibration is detected, the turbine yaws to better align with the wind. This uses stored energy. By adjusting blade orientation, vibrations can be mitigated without grid power.

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Passive damping system for floating platforms like offshore wind turbine foundations to mitigate motion induced by waves and wind without active power consumption. The system uses compressible gas-filled containers inside the platform pontoons filled with liquid. Gas flow controllers can adjust gas flow between the containers to damp out platform motion at different frequencies. The compressible gas elements absorb and dissipate energy from environmental forces, reducing platform resonance.

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ABSTRACT The laminated composite structure with viscoelastic material inserted provides excellent performance of vibration and noise suppression, which has been extensively deployed for industrial applications, such as rail transportation. In this work, the aim is to present dynamics FGCNT reinforced (FGCNTRC) sandwich beam structures by conducting detailed parametric studies fundamental frequency (FF) loss factor (LF), give a reference engineers develop great stiffness damping. extended mixture rule method firstorder discrete layer model are applied deduce effective properties FGCNTRC faces differential equations structures, respectively. Five stacking configurations considered. Subsequently, Hamilton approach build equations, these solved using Navier method. Finally, change structural damping explored, follows: First, FF gradually becomes large, LF decreases volume fraction CNTs enlarging. Second, dimensionless increases, first increases then enlarging thickness ratio two layers. Third, enlarge h 2 / ratio, always diminishes, but when bigger, rises smaller, gradually.

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Studies that involve mitigating aerodynamic noise in rotating components such as rotors of wind turbines or propellers Unmanned Aerial Vehicles have gained immense interest the research community over last few years. The present study explores mitigation potential passive compliant coatings through Computational Aeroacoustics Analysis (CAA) and experimentation tunnel testing. CAA was performed on a flat plate for chord-based Reynolds number Re c = 460,000 using SST k- Improved Delayed Detached Eddy Simulation Ffowcs Williams Hawkings acoustic analogy. Trailing edge (TE) accurately predicted from 750 to 7000 Hz. Noise results were compared with cases where different material properties are applied onto plate. It observed coating-1 (Dow Corning Silastic S-2) may increase TE by 10 15 dB/Hz throughout frequency range interest, an Overall Sound Pressure Level (OASPL) 2.89 dB. Whereas coating-2 Sylgard 184) shifted energy content lower reduced 2 4 600 1575 Additionally, it resulted 1.85 dB reduction OASPL, thus demonstrating choice coating materials viscoelastic plays crucial role... Read More

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Considering that the existing research on motor using structure optimization to reduce noise is difficult further meet requirements of low noise, from transmission path, a new method viscoelastic free damping vibration and reduction based high-precision positioning sound source proposed in this study. Based motors intensity experiment, image reconstructed compressive sensing SP algorithm locate primary precisely. For design layer laying scheme, study theoretical influence storage modulus, Poissons ratio, thickness, other significant parameters asphalt material characteristics housing necessary. The motor-free scheme refined acoustic contribution obtained simulation analysis. schemes validity verified by applying sinusoidal sweep excitation. optimized experiments under multiple working conditions, experimental comparison results validate power level with accurately laid can be reduced up 4 dB(A).

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As the size and flexibility of wind turbine blades increase, aeroelastic challenges faced by turbines become more pronounced. To prevent blade damage due to vibration improve stability blades, this paper proposes a bionic with web inspired bamboo honeycomb structures. The fluid-solid interaction analysis is conducted using computational fluid dynamics finite element method, based on Shear Stress Transport (SST) k-w turbulence model. displacements, stresses, strains, modal, harmonic response analyses both original are evaluated underrated operating conditions. results indicate that, compared blade, maximum displacement reduced 10.1%, stress value surface 2.1% lower, strain 2.5% lower. buffers loads in stages during deformation leading improved resistance.

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One of nature's most plentiful energy sources is a wind conversion system, which also has higher sustainability and no pollution. Damping controllers are designed to enhance hybrid robustness adaptability when using permanent magnet double-fed induction synchronous generators. The generators integrated with convectional sources, requires careful consideration grid stability (rotor angle stability), helps prevent mechanical oscillation disruptions due the instability. Power system stabilizers excitation optimized assure power stabilizer settings for ideal damping performance ignore losses; essential.

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Wind turbine blade vibration reduction device to suppress blade vibrations and prevent aeroelastic instability in large wind turbine blades. The device involves a series of vibration damping units arranged inside the blade between the webs. Each unit has two impact dampers in separate cavities separated by partitions. The dampers contain pendulum balls connected by springs and ropes to the blade webs and cavities. The pendulum balls collide as the blade oscillates, dissipating energy and reducing amplitude. Rubber pads isolate the dampers from the blade shell. The one-way energy dissipation device minimizes blade deformation, extends blade life, and prevents instability.

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A resonance control device for wind turbines to reduce vibrations and noise. It consists of a housing with sound-absorbing material, a vibration sensor, and a rotating block. The vibration sensor detects turbine vibrations and transmits the signal to a steering gear. This gear adjusts the fan blade angle to counteract the vibrations and prevent resonance. The rotating block allows the sensor and gear to rotate with the turbine. The housing absorbs noise from the turbine. This setup reduces vibrations and noise by actively mitigating resonance.

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Passive aerodynamic damping structure for wind turbine blades to suppress blade vibrations under unstable airflow conditions. The damping structure has lobes and a rotary mechanism mounted at the blade tip. The lobes are eccentrically positioned around the rotary mechanism's axis. This offset creates a lever arm that activates the lobes when the blade vibrates. The lobes generate aerodynamic forces that dampen the vibrations. The lobes are positioned near the blade's aerodynamic center to maximize damping effect. The rotary mechanism allows blade rotation under stable airflow.

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Vibration damping system for wind turbines that improves damping capacity as wind direction and force change during operation. The system uses adjustable damping units with movable rings that cooperate to generate resistance to damp vibrations. This provides better damping compared to fixed dampers as the movable rings can adapt to different vibration frequencies and amplitudes caused by changing wind conditions.

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Vibration absorber for generator stators to reduce vibrations in large turbine generators. The absorber uses the principle of a dynamic vibration absorber. It attaches to the generator stator housing and has a support base, vibration absorbing elastic plates, a counterweight cavity, and a counterweight block. The absorber has the same natural frequency as the generator to effectively reduce stator vibrations.

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Real-time vibration control system for wind turbines that can actively and accurately mitigate turbine vibrations during operation. The system uses a movable mass block on the tower that can be adjusted by a controller to change the overall mass distribution of the turbine. By moving the mass block to positions with maximum vibration displacement, the natural frequency of the turbine can be altered in real time to break away from resonance frequencies. This allows the turbine to operate farther from vibration frequencies caused by wind load, preventing resonance and reducing overall vibration amplitudes.

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Vibration and noise reduction device for wind turbines that mitigates the high-frequency vibrations and noise generated by wind turbine generators. It uses a base in the nacelle, a damping chamber filled with non-Newtonian fluid, a sliding linkage connecting to the turbine, and an elastic component between the linkage and base. The fluid-filled chamber and elastic component absorb and dissipate vibrations and noise from the turbine to reduce transmission to other equipment in the nacelle.

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A composite multi-system wind turbine vibration reduction and load reduction mechanism that aims to mitigate vibrations and loads in wind turbines without external energy. The mechanism uses a passive vibration control system that can be integrated into the wind turbine structure. It consists of a composite multi-system that includes a yaw system, a gear system, and a fluid system. The yaw system has wheels and a connecting rod that connects to the gear system. The gear system has a pair of gears with teeth that engage. The fluid system has a tank with liquid that sloshes when the turbine vibrates. The composite multi-system is tuned to the turbine's vibration frequencies. When the turbine vibrates, the fluid sloshing absorbs energy, the gears transmit forces, and the wheels rotate to dampen the vibrations.

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A wind turbine vibration damping device using non-Newtonian fluid to reduce vibrations in wind turbines. The device consists of a base, shell, elastic component, and a non-Newtonian fluid damping assembly. The shell slides on the base, with the turbine mounted on it. The elastic component connects the base and shell. The non-Newtonian fluid damping assembly is between the shell and turbine. This configuration uses the unique properties of non-Newtonian fluids to dampen vibrations when the turbine is operating. The non-Newtonian fluid resists deformation when forces are applied, which helps absorb and dissipate vibrations. The device allows the turbine to slide on the shell, reducing fixed-point vibrations. The elastic component provides compression, and the non-Newtonian fluid damping assembly absorbs and reduces vibrations further.

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Large wind turbine blade vibration damping system using spherical liquid masses inside the blades to reduce blade vibrations and prevent damage. The system has multiple spherical liquid masses connected in series inside the blade. Each mass is a hollow sphere with a sealed hemisphere, a tuning liquid, partition plate, disc-shaped steel plate, springs, limiting devices, and friction pads. The disc-shaped steel plate can rotate freely around a ball joint. When the blade vibrates, the sloshing liquid creates forces to counteract the vibrations. The disc rotation is limited, springs dampen motion, and friction pads increase energy dissipation.

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Device and method to mitigate blade vibrations in wind turbines during stationary periods like installation or shutdown. The device is a removable flexible sleeve that wraps around part of the blade and attaches near the leading edge. It has airflow altering elements like dimples filled with material. This modifies airflow around the blade to reduce vibrations compared to normal operation. The removable attachment near the leading edge allows easy removal after installation.

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Compact damping device with integrated frequency adjustment for vibration control in structures like wind turbine towers. The device has a base with an internal cavity containing an elastic member and a damping component. A connector extends from the base into the cavity and can move relative to the base. The elastic member attaches to the connector and base, adjusting frequency. The damping component is connected to the connector and base, absorbing vibration energy. This integrated design avoids separate frequency and damping components scattered in the structure.

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