Examining the impact of the ‘visitor effect’ and weather variables on the behavior of Chilean flamingos (Phoenicopterus chilensis) via webcam

Today’s wind turbines are designed in a wide range of vertical and horizontal axis types. In this study, several wind turbines are designed for low wind speed areas around the world mainly for domestic energy consumption. The wind speed range of 4–12 mph is considered, which is selected based on the average wind speeds in the Atlanta, GA and surrounding areas. These areas have relatively low average wind speeds compared to various other parts of the United States. Wind energy has been identified as an important source of renewable energy. Traditionally wind energy utilization is limited to areas with higher wind speeds. In reality a lot of areas in the world including Atlanta, GA., have low average wind speeds and demand high energy consumption. In most cases, wind turbines are installed in remote offshore or away from habitat locations, causing heavy investment in installation and maintenance, and loss of energy transfer over long distances. Therefore, the main focus of this study is to extract wind energy domestically at low wind speeds. A few more advantages of small scale wind turbines include reduced visibility, less noise and reduced detrimental environmental effects such as killing of birds, when compared to traditional large turbines. With the latest development in wind turbine technology it is now possible to employ small scale wind turbines that have much smaller foot print and can generate enough energy for small businesses or residential applications. The low speed wind turbines are typically located near residential areas, and are much smaller in sizes compared to the large out of habitat wind turbines. In this study, several designs of wind turbines are modeled using SolidWorks. Virtual aerodynamic analysis is performed using SolidWorks Flow simulation software, and then optimization of the designs is performed based on maximizing the starting rotational torque and acceleration. From flow simulations, forces on the wind turbine blades and structures are calculated, and used in subsequent stress analysis to confirm structural integrity. Critical insight into the low wind speed turbine design is obtained using various configurations and the results are discussed. The study will help identify bottlenecks in the practical and effective utilization of low speed wind energy, and help devise possible remedial plans for the areas around the globe that get low average wind speeds.

Wind energy has been identified as an important source of renewable energy. In this study, several wind turbine designs have been analyzed and optimized designs have been proposed for low wind speed areas around the world mainly for domestic energy consumption. The wind speed range of 4–12 mph is considered, which is selected based on the average wind speeds in the Atlanta, GA and surrounding areas. These areas have relatively low average wind speeds compared to various other parts of the United States. Traditionally wind energy utilization is limited to areas with higher wind speeds. In reality a lot of areas in the world have low average wind speeds and demand high energy consumption. In most cases, wind turbines are installed in remote offshore or away from habitat high wind locations, causing heavy investment in installation and maintenance, and loss of energy transfer over long distance. A few more advantages of small scale wind turbines include reduced visibility, less noise and reduced detrimental environmental effects such as killing of birds, when compared to traditional large turbines. With the latest development in wind turbine technology it is now possible to employ small scale wind turbines that have much smaller foot print and can generate enough energy for small businesses or residential applications. The low speed wind turbines are typically located near residential areas, and are much smaller in sizes compared to the large out of habitat wind turbines. In this study, several designs of vertical and horizontal axes wind turbines are modeled using SolidWorks e.g. no-airfoil theme, airfoil blade, Savonius rotor etc. Virtual aerodynamic analysis is performed using SolidWorks Flow simulation software, and then optimization of the designs is performed based on maximizing the starting rotational torque and ultimate power generation capacity. From flow simulations, forces on the wind turbine blades and structures are calculated, and used in subsequent stress analysis to confirm structural integrity. Critical insight into low wind speed turbines is obtained using various configurations, and optimized designs have been proposed. The study will help in the practical and effective utilization of wind energy for the areas around the globe having low average wind speeds.

Relevance Wind power in the Republic of Bashkortostan, as in any other region, has its drawbacks. Bashkortostan is not a region with a high level of wind energy. According to meteorological stations, the average annual wind speed at a height of up to 10 m varies from 1.6 to 4.4 m/s. The nominal wind speed at which the wind generator produces maximum power is in the range of 12–15 m/s. To solve the problem of generating electricity in areas with low wind speed, where the potential of wind energy is small, new technical solutions are needed. One of them is proposed in this article in the form of a wind turbine based on two five-phase magnetoelectric generators with voltage stabilization. Aim of research To investigate the possibility of stabilizing the output voltage at low wind speeds in a wind turbine based on two five-phase magnetoelectric generators. Research methods Modeling of operating modes at low and normal wind speeds of a wind turbine based on two five-phase magnetoelectric generators in the Matlab (Simscape) software package. Results A study was conducted of the operating modes at low and normal wind speeds of a wind turbine based on two five-phase magnetoelectric generators in the Matlab (Simscape) software package. Such a method of voltage regulation can provide the ability to stabilize the voltage and maintain high efficiency at an acceptable level in a wider range of low and normal wind speeds.

Levels of particulate matter and meteorological variables (atmospheric temperature, relative humidity and wind speed) for 2009 to 2011were analyzed and evaluated. Data used in this paper were obtained from an ambient air quality station located in the western desert of Abu Dhabi Emirate-United Arab Emirates. The variation patterns of PM10 concentrations were explored, and their relationships with meteorological parameters were identified. The study area is characterized by relatively low wind speed, high temperatures and humidity and elevated levels of suspended particle concentrations. Hourly levels of PM10 were found to range between 4 to 3474µg/m 3 with 27% of the daily average values exceeding the national standard limit of 150μg/m 3 . The diurnal variation pattern of PM10 showed two concentration peaks, the first of which occurred in the afternoon whereas the second peak occurred at 16:00. The highest level of PM10 was observed on Tuesdays, while the lowest level was on Fridays. The highest main value of PM10 was observed on July where a level of 204µg/m 3 was reported and lowest level of 47µg/m 3 was reported in January. Pearson’s analysis revealed a positive correlation between PM10 and temperature, low humidity (≤13%) and wind speed conditions. On the other hand, a strong inverse relationship was observed between PM10 concentrations and relative humidity higher than 13%.

Traditional vortex-induced vibration energy harvesters could transform wind or water energy into electricity at low flowing speeds. However, it has the disadvantage of narrow working speed band, which limits wide application in velocity-changing environments. A piezoelectric harvester with an inner beam for harvesting wind energy at both low and high wind speed regions is presented. A comprehensive nonlinear distributed fluid–solid–electric governing equations for vortex-induced vibration piezoelectric energy harvesting are derived and the theoretical results show that dimensions of outer beam and diameter of attached cylinder can affect optimal wind speed and maximum power output at both low and high wind speeds. In contrast, the dimensions of the inner beam and mass block only have impacts at high wind speeds. The equivalent circuit modeling method is utilized to analyze energy harvesting output characteristics. Analogies between mechanical and electrical domains are built, and the governing equations are converted to circuit equations. Then the circuit equations are settled in electrical software for time-varying analysis. The electrical circuit simulation results show that the optimal load resistance is 400 kΩ at low wind speed and 500 kΩ at low wind speed, which is consistent with theoretical results. The prototypes were fabricated and experiments were carried out in a wind tunnel. Experimental results indicate that energy harvester could generate power at both low and high speeds. Mass block has great impact on optical speed and working wind speed band. The energy harvester with 7.06 g mass block could output 127.36 μW at 2.65 m s−1 and 63.63 μW at 4.4 m s−1. Numerical and circuit simulation results are consistent with experimental results on optical load resistances and optical wind speeds. This design provides a feasible method for broadening wind speed region for energy harvesting.

Wind speed adaptive triboelectric nanogenerator with low start-up wind speed, enhanced durability and high power density via the synergistic mechanism of magnetic and centrifugal forces for intelligent street lamp system

An optimization framework for load and power distribution in wind farms: Low wind speed

Estimating reference evapotranspiration with atmometers in a semiarid environment

Icing on transmission line becomes more serious in the past ten years, and the icing area gradually expanded from the traditional south to northeast area. Ice melting is an effective method to deal with the icing disaster. But the existing ice-melting research mainly focuses on traditional ice-coated areas with low wind speed and mild temperature. But it is difficult to apply to northern regions and alpine mountainous areas with low temperature and high wind speed conditions. In response to such issue, this paper establishes an equivalent thermal circuit model for ice melting process, and studies the quantitative effects of wind speed and temperature on the characteristics of ice melting current, and obtains the law of melting ice current under low temperature and high wind speed.it provides information for the parameter design of ice melting system in extremely cold regions.

It is well known that energy generated by a wind generator (WG) depends on the wind resources at the installation site. In other words, a WG installed in a high wind speed area can produce more energy than that in a low wind speed area. However, a WG installed at a low wind site can produce a similar amount of energy to that produced by a WG installed at a high wind site if the WG is designed with a rated wind speed corresponding to the mean wind speed of the site. In this paper, we investigated the power curve of a WG suitable for Korea's southwestern coast with a low mean wind speed to achieve a high capacity factor (CF). We collected the power curves of the 11 WGs of the 6 WG manufacturers. The probability density function of the wind speed on Korea's southwestern coast was modeled using the Weibull distribution. The annual energy production by the WG was calculated and then the CFs of all of the WGs were estimated and compared. The results indicated that the WG installed on the Korea's southwestern coast could obtain a CF higher than 40 % if it was designed with the lower rated speed corresponding to the mean wind speed at the installation site.

In recent years, sites with low annual average wind speeds have begun to be considered for the development of new wind farms. The majority of design methods for a wind turbine operating at low wind speed is to increase the blade length or hub height compared to a wind turbine operating in high wind speed sites. The cost of the rotor and the tower is a considerable portion of the overall wind turbine cost. This study investigates a method to trade-off the blade length and hub height during the wind turbine optimization at low wind speeds. A cost and scaling model is implemented to evaluate the cost of energy. The procedure optimizes the blades’ aero-structural performance considering blade length and the hub height simultaneously. The blade element momentum (BEM) code is used to evaluate blade aerodynamic performance and classical laminate theory (CLT) is applied to estimate the stiffness and mass per unit length of each blade section. The particle swarm optimization (PSO) algorithm is applied to determine the optimal wind turbine with the minimum cost of energy (COE). The results show that increasing rotor diameter is less efficient than increasing the hub height for a low wind speed turbine and the COE reduces 16.14% and 17.54% under two design schemes through the optimization.

The effectiveness of a wind turbine to transform wind energy in electrical energy on a specific site depends heavily on its design, above all on the generator to rotor (turbine) ratio (GRR). In this research, the optimization of the GRR is focused with respect to the cost of energy (COE). Using a wind speed, a power generation, and a cost model, the Annual Energy Production (AEP) and the COE can be calculated dependent on the average wind speed, which is a site characteristic. The optimal GRR is shown with respect to the plant size and the wind class. A sensitivity function is interpolated which gives an idea for which type of site a plant is convenient. Moreover, the performance of existing plants has been evaluated for sites with low average wind speed conditions, where the funding and convenience of a wind park is particularly critical. As a result of the optimization, a reference plant design is proposed, which is optimal with respect to the models and reduces the COE in low average wind speed conditions.

Background: The objective of this study was to evaluate the impact of weather factors on stroke parameters. Methods: This retrospective study analyzed the records of stroke patients concerning the influence of meteorological conditions and moon phases on stroke parameters. Results: The study group consisted of 402 patients aged between 20 and 102; women constituted 49.8% of the subjects. Ischaemic stroke was diagnosed in 90.5% of patients and hemorrhagic stroke was diagnosed in 9.5% of patients. The highest number of hospitalizations due to stroke was observed in January (48 events); the lowest number was observed in July (23 events). There was no statistically significant correlation between the meteorological parameters on the day of onset and the preceding day of stroke and the neurological status (NIHSS) of patients. Mean air temperature on the day of stroke and the day preceding stroke was significantly lower in the group of patients discharged with a very good functional status (≤2 points in modified Rankin scale (mRS)) compared to the patients with a bad functional status (>2 points in mRS); respectively: 7.98 ± 8.01 vs. 9.63 ± 7.78; p = 0.041 and 8.13 ± 7.72 vs. 9.70 ± 7.50; p = 0.048). Humidity above 75% on the day of stroke was found to be a factor for excellent functional state (RR 1.61; p = 0.016). The total anterior circulation infarcts (in comparison with stroke in the other localization) were more frequent (70%) during a third quarter moon (p = 0.011). The following parameters had a significant influence on the number of stroke cases in relation to autumn having the lowest number of onsets: mean temperature (OR 1.019 95% CI 1.014–1.024, p < 0.000), humidity (OR 1.028, CI 1.023–1.034, p < 0.0001), wind speed (OR 0.923, 95% CI 0.909–0.937, p < 0.0001), insolation (OR 0.885, 95% CI 0.869–0.902, p < 0.0001), precipitation (OR 0.914, 95% CI 0.884–0.946, p < 0.0001). Conclusion: Air humidity and air temperature on the day of stroke onset as well as air temperature on the day preceding stroke are important for the functional status of patients in the acute disease period. A combination of the following meteorological parameters: lowered mean temperature and low sunshine, high humidity and high wind speed all increase the risk of stroke during the winter period. High humidity combined with high precipitation, low wind speed and low sunshine in the autumn period are associated with the lowest stroke incidence risk. A possible relationship between phases of the moon and the incidence requires further investigation.

The utilization of the wind energy at a location primarily depends on the wind speed and right kind of machine installed at the site. The selection of machine for a site needs to be in such a way, so that maximum amount of energy can be effectively harnessed from the available wind spectrum. Wind speeds in the North-Eastern region of India are relatively low, highly fluctuating in directions, and localized in nature. The low wind speed creates difficulty to provide high starting torque to larger capacity machines with relatively higher rated wind speed. Thus, the region could be favorable to smaller machines having low cut-in and low rated wind speed. The present work aims to analyze the feasibility of installation of low capacity wind machines by estimating the capacity factors and annual energy generation at selected sites of the region. The low capacity machines can be used as an off-grid energy system to provide electricity access in the remote locations of the region.

Based on the assumption that taking the KPP model as the vertical vortex viscosity coefficient, the unsteady Ekman equation modified by wave and linear friction terms is solved numerically with the finite difference method and the influence of wave and linear friction terms on the unsteady Ekman current are studied. Based on the measured data of AWAC, the Stokes drift is calculated by the Stokes drift formula; and on the basis of the measured data of wind speed, the average wind speed of the 3 hours is divided into three different sections: low wind speed (0∼4) m/s, medium -low wind speed (4∼8) m/s and medium-high wind speed (8∼12) m/s. The results show that: Stokes drift has the greatest impact on Ekman current under the low wind speed, which is accounted for 27.4%, the second is under the medium-low wind speed of 7.5%, and the smallest effect is under the medium-high wind speed of 4.2%. In additon, the effect of linear friction term on Ekman current is also studied. It is shown that under the medium-high wind speed and the medium-low wind speed, together with the ratio of the linear friction term to the Coriolis force is, the influence of the linear friction term on the Ekman current has exceeded that of the Stokes drift on the Ekman current; while under the low wind speed, the effect of linear friction term on Ekman current can not exceed that of Stokes drift on Ekman current until. Furthermore, the comparison between the numerical solution and the actual measured data also shows different characteristics. In the perspective of relevance, the correlation between the numerical simulation results and the measured data is above 0.7 under the medium-high wind speed, which is higher than the correlation between the both of 0.4∼0.5 under the low wind speed and the medium-low wind speed; and in the perspective of the root mean square deviation degree, the root mean square deviation between the numerical simulation results and the measured data under the medium-high wind speed is lower than that under the low wind speed and the medium-low wind speed. The above results show that the influence of Stokes drift, linear friction term and the unsteady wind on Ekman model can not be ignored.