Wide Range Of Wind Speeds Research Articles

Study of wind energy harvesting based on rolling bearing type triboelectric nanogenerator

This research developed a novel rolling bearing type triboelectric generator (RB-TENG) designed to efficiently harvest wind energy across a broad spectrum of wind speeds. This generator consists of a column stator shell made of rigid transparent resin. The inside of the stator is open with a circular track affixed with four pairs of copper electrodes, which rub against PTFE balls, using the independent layer operating mode of the triboelectric nanogenerator, due to the use of rolling friction pairs with the collection of a wide range of wind speeds, as low as 2.5 m/s wind speed can be collected. RB-TENG uses rolling friction instead of sliding to extend its service life. The experimental results show that within the wind speed range of 2.5 m/s to 8 m/s, the output performance of RB-TENG increases randomly with the increase of wind speed, and the numerical growth is not very significant after the wind speed of 6 m/s. The effective power density measured at a wind speed of 8 m/s was 5.07 mW/m2. Furthermore, experiments validate the RB-TENG's capability to power small appliances and its potential applicability in sea farms. It provides a viable solution to reducing reliance on fossil fuels and offers a multi-purpose strategy based on wind energy.

A hybrid fuzzy logic-based MPPT algorithm for PMSG-based variable speed wind energy conversion system on a smart grid

Recently, wind power has gained popularity as a sustainable energy source. Wind energy conversion systems (WECSs) can accept fixed speed and variable speed (VS) operations. VS-WECSs are preferable to conventional WECSs because of their higher electricity collection capacity. Maximum power point tracking systems (MPPTs) are essential for maximizing the efficiency of wind energy generation in wind turbine installations linked to power grids. This study introduces a hybrid fuzzy logic controller-based MPPT (FLC-MPPT) for wind turbines (WTs) connected to permanent magnet synchronous generators (PMSGs) to accurately determine the maximum power output of WTs. This study employs a three-phase back-to-back converter to link a PMSG to a utility grid. The reference signals for pulse width modulation controllers comprise two-phase system currents. It constructs a converter that can transfer electrical energy in both directions using insulated-gate bipolar transistor technology and is powered by a battery. The machine-side converter uses model predictive control for the present control loop. Given the generator's susceptibility to changes in wind conditions, this factor is of the utmost importance. A WT simulation was conducted using MATLAB/Simulink and an FLC methodology was employed. The model used a PMSG. Measurements of rotor speed, power, induced voltage, and current were taken in relation to variations in wind speed. The simulation results show that the FLC-MPPT can maximize the output power over a wide range of wind speeds with a higher efficiency of 92.6% and performance of 95.7%.

Metasurface-enhanced multifunctional flag nanogenerator for efficient wind energy harvesting and environmental sensing

Wind energy, as a widely distributed and renewable energy resource, plays a crucial role in promoting self-powered wireless sensor networks and wind speed sensing. However, current research predominantly focuses on specific application purposes, lacking comprehensive investigations into integrated solutions. In this paper, a metasurface-enhanced multifunctional flag-type triboelectric nanogenerator (FTENG) is introduced, which enables efficient wind energy harvesting as well as accurate wind speed sensing over a wide range of wind speeds via the synergistic effect of metasurface treatment on the flagpole and flexible flag fixation approach. The flexible fixation maximally utilizes the upstream wake of metasurface configurations, boosting the energy harvesting power density by up to 23 times. The metasurface-enhanced FTENG with careful optimization, striking a balance between energy harvesting and sensing capabilities, achieves a linearity of 0.992 over a wind speed range of 2.3–14.4 m/s and a peak power density of 250 mW/m2. Finally, the FTENG demonstrates its excellent abilities to light LEDs, power the wireless sensor node (WSN), and serve as a self-powered environmental sensor. This work opens up an impactful possibility for developing versatile self-powered electronics by employing metasurface-enhanced wind energy harvesting techniques.

Wind-Speed-Adaptive Resonant Piezoelectric Energy Harvester for Offshore Wind Energy Collection.

This paper proposes a wind-speed-adaptive resonant piezoelectric energy harvester for offshore wind energy collection (A-PEH). The device incorporates a coil spring structure, which sets the maximum threshold of the output rotational frequency, allowing the A-PEH to maintain a stable output rotational frequency over a broader range of wind speeds. When the maximum output excitation frequency of the A-PEH falls within the sub-resonant range of the piezoelectric beam, the device becomes wind-speed-adaptive, enabling it to operate in a sub-resonant state over a wider range of wind speeds. Offshore winds exhibit an annual average speed exceeding 5.5 m/s with significant variability. Drawing from the characteristics of offshore winds, a prototype of the A-PEH was fabricated. The experimental findings reveal that in wind speed environments, the device has a startup wind speed of 4 m/s, and operates in a sub-resonant state when the wind speed exceeds 6 m/s. At this point, the A-PEH achieves a maximum open-circuit voltage of 40 V and an average power of 0.64 mW. The wind-speed-adaptive capability of the A-PEH enhances its ability to harness offshore wind energy, showcasing its potential applications in offshore wind environments.

Direct wind-powered vertical axis brackish water desalination system

The supply of freshwater based on wind-powered desalination is technically feasible, but energetic losses associated with conventional systems necessitate new approaches. This study explores a direct wind-powered desalination (D-WPD) system using a small-scale vertical axis wind turbine (VAWT) for reverse osmosis via a high-pressure pump without electricity generation or a system controller. A comprehensive parametric study examined the effects of feed water salinity, loading, and wind speed on the system's performance, demonstrating high efficiency under various operating conditions. A stand-alone system demonstrated operation at effectively constant system efficiency, approximately 13.5 %, and low specific energy consumption for a wide range of wind speeds and salinities. Despite the turbine's small projected area of 0.8 m2, the D-WPD system yielded a daily permeate production of up to 0.6 m3/day at an average wind speed of 6 m/s. The D-WPD system surpassed previous wind-powered desalination studies in terms of specific energy consumption, relative efficiency, and relative desalination capacity. Leveraging the environmental benefits of the slow-spinning VAWT, this D-WPD offers a cost-effective off-grid solution for small-scale desalination.

State-of-the-art review of micro to small-scale wind energy harvesting technologies for building integration

The utilisation of wind power in buildings has gained significant interest, but deploying wind turbines in built environments presents unique challenges due to highly turbulent wind patterns. Existing small wind turbines may not be as efficient in such complex conditions, and their transient loads and vibrations can compromise their durability. This study aims to assess the recent status, challenges, and limitations of building-integrated wind turbines and micro or small-scale wind-induced vibration technologies to enhance their performance, efficiency, reliability, and cost-effectiveness. The research evaluates advancements, applications, and technical features that optimise these technologies to function effectively in non-uniform wind flows and a wide range of wind speeds. Modeling conventional systems, including horizontal axis and vertical axis wind turbines, is well-established using computational fluid dynamics and blade element momentum methods. Micro or small-scale wind-induced vibration technologies have demonstrated power outputs ranging from milliwatts to kilowatts, making them suitable for powering actuators and low-powered sensors used in buildings. The study emphasises the importance of harnessing wind velocity acceleration induced by the building's roof shape when incorporating wind energy harvesting technologies. Nevertheless, research on wind-induced vibration harvesting primarily takes place in controlled environments, neglecting the influence of real buildings. This represents a significant research gap, considering the potential for wind-induced vibration technologies to provide power to off-grid communities and facilitate building integration. The lack of comprehensive analysis concerning the energy, economic, and environmental aspects of micro-energy harvesting technologies hinder their widespread adoption and a comprehensive understanding of their potential. Addressing these research gaps is essential to promote the implementation and efficacy of micro-scale wind energy harvesting technologies in various real-world scenarios.

Modelling of Lake Waves to Simulate Environmental Disturbance to a Scale Ship Model

Abstract In the development of ship motion control systems, software simulations or scale model experiments in pools or open water are very often carried out in the verification and testing stages. This paper describes the process of building a software wave simulator based on data gathered on the Silm Lake near Iława, Poland, where scale ship models are used for research and training. The basis of the simulator structure is a set of shaping filters fed with Gaussian white noise. These filters are built in the form of transfer functions generating irregular wave signals for different input wind forces. To enable simulation of a wide range of wind speeds, nonlinear interpolation is used. The lake wave simulation method presented in this paper fills a gap in current research, and enables accurate modelling of characteristic environmental disturbances on a small lake for motion control experiments of scale model ships.

Experimental study of shear-driven water film with brightness-based laser-induced fluorescence technique

Driven by low-temperature and high-speed airflow, the water droplets impinging the surface of the aircraft will gather into water film, affecting the aerodynamic characteristics and endangering flight safety. In this paper, a high-speed video system with the brightness-based laser-induced fluorescence (BBLIF) technique was used to analyze the transient water film thickness and wavy characteristics on a horizontal metal plate. A series of experiments were performed over a wide range of wind speeds (15.59 m/s ∼ 52.20 m/s) and water volume flow rates (100 ml/min ∼ 900 ml/min). According to the interfacial phenomena observed in the experiment, the water film flow is classified into five regimes: two-dimension-wave, ripple-wave, dual-wave, roll-wave, and entrainment. The water film characteristics such as mean film thickness, film roughness, wave frequency, and rolling wave intermittency are studied under the influences of air velocity and water flow rate. The results show that the complex fluctuation characteristics of water film are the result of the joint action of surface tension, interfacial shear force and inertia term of water film, and are closely related to the water film flow regime. The findings could contribute to a better understanding of the shear-driven water film wavy characteristics and the optimization of the anti-icing or de-icing system.

Post critical characteristics of a side-box steel concrete composite girder: Experimental investigation and mechanism analysis

The present study is aimed to investigate the post-critical behavior of a side-box steel-concrete composite girder under varying wind angles of attack, by conducting a series of section model testing with single-degree and two-degrees of freedom. The essence of flutter, as well as the adverse impact of vortex shedding lock-in on exacerbating post-critical flutter responses, was revealed in detail. The results indicate that the coupled motion of flutter for the prototype composite girder can be characterized as a supercritical Hopf bifurcation with significant phase shifting between motions. The circular character of the limit cycle oscillation (LCO) expressed in the phase diagram is altered to a non-circular form due to the apparent aerodynamic stiffness nonlinearity within a wide range of wind speeds. Interestingly, the coupling vibration between vortex-induced vibrations (VIV) and flutter, i.e., VIV-flutter coupling vibration is observed for the prototype girder, due to the evolution of total damping ratio concave shape with wind speed. Two mitigation countermeasures, i.e., a L-shaped skirt plate and a sharpened wind fairing, were proposed to improve the aeroelastic stability, caused by a significant increase in uncoupled positive aerodynamic damping and alternation of VIV-flutter coupling. In addition, the specific effects of structural damping on the VIV-flutter coupling were discussed in detail.

An in-plane omnidirectional flutter piezoelectric wind energy harvester

Most wind energy harvesters that are based on wind-induced vibrations can only operate in a specific wind direction, which limits their application in environments with time-varying wind directions. Previously reported in-plane omnidirectional piezoelectric wind energy harvesters (PWEHs) based on vortex-induced vibrations can produce stable electrical output characteristics when the wind direction changes, but their output powers are relatively low and the working wind speed ranges are relatively narrow. To solve this issue, this work presents an in-plane omnidirectional flutter PWEH which is mainly composed of the bluff body of a hollow cylindrical shell and the inside elastic supporting structure of several piezoelectric composite beams. Finite element analysis shows that harvesters with both four and six supporting beams offer good stiffness and electromechanical conversion isotropies. Experiments demonstrate that both prototype devices are flutter PWEHs with rotation axes located on the rear of the geometrical center of the bluff body. The effect of wind speed on their directionality is small, and both prototypes show in-plane omnidirectional operation over a wide wind speed range, over which the electrical outputs remain relatively high. The prototype with six beams is preferred from the viewpoint of the wind direction adaptability. The onset wind speeds in different directions all range between 5.8 and 6.0 m/s, showing the good isotropy. The minimum and maximum powers are approximately 266.4 and 300.1 μW, respectively, at 10 m/s, and it shows in-plane omnidirectional energy harvesting performance in the wind speed range from 6.5 m/s up to more than 10 m/s.

Experimental investigation and analysis of proposed hybrid vertical axis wind turbine design

In this research, an experimental and computational analysis of a novel hybrid vertical axis wind turbine (VAWT) arrangement has been performed. We suggest an innovative VAWT design that has a high power coefficient and self-starting capability. The inner side of the proposed hybrid system has been integrated with the H-rotor turbine with cambered blades, which demonstrates strong self-starting capabilities at various azimuths. Three NACA0018 airfoil blades are mounted on the outside of the proposed hybrid wind turbine, while three DU 06-W-200 airfoil blades are installed on the inside. Based on a similarity analysis, a scaled-down model was developed, and performance characteristics such as the output power, power coefficient ([Formula: see text]), dynamic torque coefficient ([Formula: see text]), and static torque coefficient ([Formula: see text]) were determined. An existing hybrid VAWT and a typical H-rotor Darrieus design were also examined for comparison. The highest [Formula: see text] for the proposed hybrid design was found to be 0.486 at a tip speed ratio (TSR) of 3, while the H-rotor Darrieus’ maximum value was 0.42 at a TSR of 2.62 and the existing hybrid VAWT’s value was 0.41 at a TSR of 2.5. Positive [Formula: see text] values at all azimuths demonstrate that the proposed hybrid wind turbine can start entirely on its own. In comparison to the existing H-rotor and hybrid VAWT, this novel hybrid system has shown enhanced performance parameters ([Formula: see text], [Formula: see text], [Formula: see text], output power) by around 11%–13% over a wide range of wind speeds.

Physical intelligence-based working mode adaptable triboelectric nanogenerator for effective wind energy harvesting in broad range

Triboelectric nanogenerators (TENGs) offer a promising solution for harvesting wind energy, which is a renewable source of natural energy that can be dissipated. However, designing a wind energy harvester presents a significant challenge due to the dynamic characteristics of ambient wind, including irregularity and broad wind speed ranges. In this work, we suggested a spontaneous working mode changeable TENG (SM-TENG) designed for effectively harvesting wind energy within a broad range of wind speeds ranging from a breeze of 2 m/s to a gale of 25 m/s. The SM-TENG consists of a physical intelligence-based rotator that can switch contact and separation mode depending on the input wind speed. Under a breeze, the SM-TENG can generate triboelectricity by fluttering a dielectric film based on vertical contact separation (F-TENG) due to intentional pressure imbalance. Meanwhile, when wind speed exceeds a certain wind speed of 5 m/s, the SM-TENG begins to harvest more wind by rotating the rotator based on the sliding contact separation (R-TENG), indicating that the SM-TENG can harvest wind by selecting the appropriate working mode. We adopted the Taguchi method to enhance performance by identifying the optimal parameters, affecting the desired output. In addition, the SM-TENG can successfully power a light-emitting diode display and a Bluetooth thermometer within a wide range of wind speeds. Therefore, this work may provide a strategy for designing a wind energy harvester capable of harvesting in a wide range of wind as well as 0could contribute to the feasibility of Internet of Things through distributed energy.

Numerical study on the forced convection enhancement of flat-roof integrated photovoltaic by passive components

Photovoltaic (PV) modules installed on flat roof need to be cooled to improve the power conversion efficiency (PCE). The efficient use of natural wind for cooling is a low-cost alternative compared with the use of artificial cooling devices. In this study, a passive cooling scheme is proposed including components: curved eave and vortex generators (VGs) which is arranged on the roof to enhance the forced convective heat exchange and reduce temperature of rooftop PV module under prevailing wind conditions. The optimum arrangement of VGs was studied, temperature reduction and PCE of rooftop PV with the scheme were evaluated. The results show that the curved eaves installed on the flat-roof leading edge improved the convective heat exchange only in the airflow separation area. And the defect that surface convective heat exchange decreased along with the flow direction was improved when multi-row array VGs were arranged. The overall convective heat exchange on rooftop PV can be improved at a wide range of wind speed by scheme using curved eaves in combination with the symmetrically arranged VGs. After using the passive cooling scheme, the ratio of forced convective heat exchange on the rooftop PV upper surface to 60%, and the maximum temperature reduction is about 5.89 ℃, and PCE of PV is improved in summer. The low-cost passive cooling scheme proposed in this paper is expected to be applied to the new-built and reconstruction of flat-roof mounted PV system.

A two-degree-of-freedom aeroelastic energy harvesting system with coupled vortex-induced-vibration and wake galloping mechanisms

Vortex-induced vibration (VIV) and wake galloping are two aeroelastic instability phenomena with similar underlying mechanisms related to vortex shedding. Inspired by this common feature, a two-degree-of-freedom (2DOF) piezoelectric aeroelastic energy harvester (PAEH) is proposed, which employs VIV and wake galloping mechanisms with their respective benefits to improve the wind energy harvesting performance in a wide wind speed range. The proposed 2DOF PAEH overcomes the limitations of conventional one-degree-of-freedom VIV and wake galloping energy harvesters, with the former being only effective in a single and narrow lock-in wind speed range and the latter failing to work at low wind speeds. The modal frequencies of the 2DOF PAEHs are easily manipulated, and the twin mechanisms improve power generation over two lock-in regions at low wind speeds by the VIV mechanism and a third power generation region at relatively higher wind speeds due to wake galloping. A coupled aero-electro-mechanical model is developed and verified by wind tunnel experiments on a prototype. The results show that the proposed harvester efficiently extracts wind energy in a wide wind speed range from 1.1 to 6 m/s. The influence of the distance between the two parallel bluff bodies, in which distance is a critical parameter, on the voltage output is experimentally investigated, revealing three distinct aerodynamic behaviors at different distances.

Triboelectric-Electromagnetic Hybrid Wind-Energy Harvester with a Low Startup Wind Speed in Urban Self-Powered Sensing.

Wind energy as a renewable energy source is easily available and widely distributed in cities. However, current wind-energy harvesters are inadequate at capturing energy from low-speed winds in urban areas, thereby limiting their application in distributed self-powered sensor networks. A triboelectric-electromagnetic hybrid harvester with a low startup wind speed (LSWS-TEH) is proposed that also provides output power within a wide range of wind speeds. An engineering-implementable propeller design method is developed to reduce the startup wind speed of the harvester. A mechanical analysis of the aerodynamics of the rotating propeller is performed, and optimal propeller parameter settings are found that greatly improved its aerodynamic torque. By combining the high-voltage output of the triboelectric nanogenerator under low-speed winds with the high-power output of the electromagnetic generator under high-speed winds, the harvester can maintain direct current output over a wide wind-speed range after rectification. Experiments show that the harvester activates at wind speeds as low as 1.2 m/s, powers a sensor with multiple integrated components in 1.7 m/s wind speeds, and drives a Bluetooth temperature and humidity sensor in 2.7 m/s wind speeds. The proposed small, effective, inexpensive hybrid energy harvester provides a promising way for self-powered requirements in smart city settings.

Wind Microturbine with Adjustable Blade Pitch Angle

The article presents the results of research on the operation of a wind microturbine model with an adjustable blade pitch angle. The physical basics of wind turbine operation and the methods of its optimal control are discussed. The results of the measurements carried out for the selected blade geometry with the possibility of adjusting the pitch angle are presented. The tests were carried out for a resistive load with a linear characteristic and for a load with a non-linear characteristic of a Li-Po battery. The results of the operation of a simple MPPT control algorithm are presented. The practical methods of controlling larger wind turbines are not optimal for small and very small turbines. The conducted research focused on determining the possibility of using blades with an adjustable angle setting, depending on the rotational speed in wind microturbines. The use of a simple mechanism for changing the pitch angle of the blades depending on the rotational speed of the turbine can increase the efficiency of the microturbine in a wider range of wind speeds.

Physics-informed long short-term memory networks for response prediction of a wind-excited flexible structure

Slender and flexible infrastructures such as sign supports, cantilever traffic signal structures and high mast lighting towers are sensitive to wind force and were reported to have fatigue-related issues due to the large-amplitude vibrations throughout thier life. Simulating wind-induced structural response can be an important step to evaluate their fatigue life and reliability. However, wind simulations are usually quite complicated. A comprehensive wind force model was usually developed by conducting multiple wind tunnel tests. However, due to the high cost of wind tunnel tests and the limitation of a wind tunnel, aerodynamic and aeroelastic coefficients were usually extracted only at certain wind speeds and wind directions. Interpolation or extrapolation methods were commonly used when coefficients were not available, which makes the simulation result questionable. In this study, a methodology was proposed to simulate wind-induced structural response with lower costs. The proposed method uses monitoring data in the field to develop long short-term memory (LSTM) networks. In training LSTM networks, only the monitoring data in regular wind condition was used. However, the trained LSTM network can still predict the wind-induced response in high and extreme wind conditions observed during the monitoring of the structure. The proposed method can be useful when simulating wind-induced structural response in a wide range of wind speeds and can be widely used on other structures suspected of having fatigue damage due to wind-induced vibrations.

Pier‐Based Measurements of Air‐Sea Momentum Fluxes Over Shoaling Waves During DUNEX

AbstractOpen‐ocean homogeneity is violated in the near shore region by wave shoaling and breaking, varying wind‐swell incidence angles, complex currents patterns, rapid bathymetric changes, and shore‐side topographic features. Consequently, existing drag coefficient parameterizations, which were largely developed in deep water, are not effective. This has an adverse impact on marine forecasts, weather and climate models, and coastal morphology prediction. There exists a critical need to identify and systematically quantify the impact of coastal processes and features on the momentum flux over a wide range of wind speeds. As part of the DUring Nearshore Event eXperiment at the Field Research Facility in Duck, NC, six months of direct flux observations were collected from a tower at the end of a 560 m pier. These were used to study the variability of the aerodynamic drag coefficient. Results show that for winds above 3 m s−1 the drag coefficient was between 15% and 50% higher for onshore winds when compared to alongshore. This is attributed to more energy in the downwind component of the flux around the dominant wave frequency for onshore winds, and is independent of wind speed. Holistically, the Coupled Ocean Atmosphere Response Experiment (COARE) algorithm over predicts the drag coefficient for shoaling waves. When separated by wind direction, COARE best predicts the drag coefficient for onshore winds. The results of this study can help the development of more robust nearshore momentum flux parameterizations. This will ultimately lead to improved weather and climate forecasting in the littoral zone, and more physically realistic short‐ and long‐term coastal resilience strategies.

Active blade pitch control and stabilization of a wind turbine driven PMSG for power output regulation

A common strategy in controlling a permanent magnet synchronous generator (PMSG) driven by a wind turbine is the maximization of output power of the wind turbine itself. A control strategy must be adopted, is to deliver a desired reduced amount of power whenever it is required. In order to realize the direct control of wind turbine output power across a wide range of wind speeds, a linearized parameter varying dynamic model of the nonlinear wind turbine system including wind disturbances is developed and used in this paper. The stability of the wind turbine system is analyzed and a blade pitch controller is designed, based on the linearized, parameter-varying, model-predictive control and is validated. Thus, the wind turbine is regulated in a way that the generator delivers the demanded power output to the load. Moreover, the blade pitch control system also performs the key function of augmenting the stability of the wind turbine, for the right choice of the gains.

Receiver Sand Mitigation Measures along railways: CWE-based conceptual design and preliminary performance assessment

Desert railways are constantly exposed to incoming wind-blown sand. The railway structure locally disturbs the incoming sand drift, induces its accumulation, and ultimately suffers its harmful effects. Receiver Sand Mitigation Measures (SMMs) aerodynamically interact with the track system, induce sand erosion around it, and allow sand transport far downwind it. The conceptual and preliminary design of an innovative Receiver SMM called Sand Blower is developed in this study. The design is grounded on the aerodynamic behaviour of the baseline humped sleeper track system. The flow control strategy is intended to avoid boundary layer separation, and to promote local flow acceleration by means of the Venturi effect. The performance assessment is carried out by Computational Wind Engineering approach. It allows to simulate the local wind flow, to obtain the shear stress field at the wall, and to derive from it sand sedimentation, windward erosion and backward erosion conditions. The results show that the Sand Blower greatly increases the track system performance by reducing sand sedimentation and increasing sand erosion under wide range of wind speeds and directions.