Performance of a prototype windmill for water pumping in Kpakungu community of Niger State Nigeria

Water is the primary source of life for mankind and one of the most basic necessities for rural development. Most rural communities in Nigeria do not have access to potable water. This research considers the provision of water to a community in Nigeria using power from wind. The design results show that a 2.076m diameter windmill is required for pumping water from borehole through a total head of 45m to meet a daily demand of 3.5m3 of water. Performance test of the horizontal axis wind pump was carried out. The lowest measured wind speed during the test was 0.4 m/s, while the corresponding water discharge flowrate was 0.032 l/s. Thehighest flowrate of 0.113 l/s was recorded at a wind speed of 2.4 m/s. Computer simulation was carried out to validate the performance test of the prototype windmill. The results showed that water discharge is proportional to the wind speed. Keywords: Energy, Kpakungu, mean wind speed, plunger, windmill

River Breezes in the Central Amazon: Cluster Analysis of Meteorological and Chemical Data Sets Collected by an Unmanned Aerial Vehicle

<p>Local atmospheric circulation induced by wide rivers in Amazonia can strongly affect the transport of urban, industrial, fire, and forest emissions. Herein, a copter-type unmanned aerial vehicle (UAV) operated from a boat was used to collect vertical profiles of meteorological parameters and chemical concentrations during Sep-Oct 2019 of the dry season. Sensor packages mounted on the UAV measured wind speed and direction together with concentrations of carbon monoxide (CO) and total oxidants (O<sub>x</sub>, defined as O<sub>3</sub> + NO<sub>2</sub>). Multivariate statistical analysis identified distinguishing patterns for meteorological variables. The occurrence of river breeze circulations was linked to meteorological conditions from in-situ measurement and satellite images. Vertical profiles of chemical concentrations both from in-situ measurements and large eddy simulations confirmed that under some conditions a river breeze can facilitate pollutant mixing perpendicular to the river orientation. The results of this study advance an urgent need to quantify the occurrence and the properties of river breeze circulations in respect to microscale chemical dispersion, air quality, and human health.</p>

Empirical Equations to Estimate Evapotranspiration in Mosul City

Average daily data of solar radiation, relative humidity, wind speed and air temperature from 1980 to 2008 are used to estimate the daily reference evapotranspiration in the Mosul City, North of Iraq. ETo calculator software with the Penman Monteith method standardized by the Food and Agriculture Organization is used for calculations. Further, a nonlinear regression approach using SPSS Statistics is utilized to drive the daily reference evapotranspiration relationships in which ETo is function to one or more of the average daily air temperature, actual daily sunshine duration, measured wind speed at 2m height and relative humidity

The effect of continuously varying wind speed on high-speed train overturning safety

Changing topography will affect wind speed variations along railway lines in local areas. When the distance from one wind speed abrupt change location to other is narrow, a continuous variation in wind speed will occur. However, few studies have focused on this topic. In this study, a continuous wind speed variation model is developed based on measured wind speed curves, the interval time of continuous wind speed changes, the wind speed amplitude variation, the wind speed change rate and peak wind speed duration on the train dynamics are investigated. The results show that continuous wind speed variations have a significant impact on the overturning safety of trains compared to a single wind speed change. When the interval time between two adjacent wind speed changes is less than 6 s, it is necessary to consider the influence of continuous wind speed variations. In addition, the influence of the wind speed amplitude changes on train overturning safety is much greater than other factors.

Can LiDARs Replace Meteorological Masts in Wind Energy?

This paper discusses whether profiling LiDARs can replace meteorological tower-based wind speed measurement for wind energy applications without severely compromising accuracy. To this end, the accuracy of LiDAR is evaluated in a moderately complex terrain by comparing long-term wind data measured by a profiling LiDAR against those obtained from tower-mounted cup and sonic anemometers. The LiDAR-measured wind speeds show good agreement with those measured using the sonic anemometer, with the slope of regression line being 1.0 and R 2 > 0.99 . Furthermore, the turbulence intensity obtained from the LiDAR has better agreement with that from the sonic anemometer compared to the cup anemometer which showed the lowest turbulence intensities among the three devices. A comparison of the turbulence intensity obtained from the 90th percentile of the standard deviation distribution shows that the LiDAR-measured turbulence intensities are mostly larger (by 2% or less) than those measured by the sonic anemometer. The gust factors obtained from both devices roughly converged to 1.9, showing that LiDAR is able to measure peak wind speed with acceptable accuracy. The accuracy of the wind speed and power distributions measured using the profiling LiDAR are then evaluated by comparing them against the corresponding distributions obtained from the sonic anemometer. Furthermore, the annual capacity factor—for the NREL 5-MW wind turbine—from the LiDAR-measured wind speed is 2% higher than that obtained from the sonic anemometer-measured wind speed. Numerical simulations are performed using OpenFAST in order to compute fatigue loads for the wind speed and turbulence distributions for the LiDAR and the sonic anemometer measurements. It is found that the 20 years lifetime Damage Equivalent Loads (DELs) computed for the LiDAR wind speed were higher than those for the sonic anemometer wind speeds, by 2%–6% for the blade root bending moments and by 11%–13% for the tower base bending moments. This study shows that even with some shortcomings, profiling LiDARs can measure wind speeds and turbulence intensities with acceptable accuracy. Therefore, they can be used to analyze wind resource and wind power potential of prospective sites, and to evaluate whether those sites are suitable for wind energy development.

Research on wind turbine power performance based on the operation Data

The power characteristics are important for evaluating the operating state of the wind turbine. In order to accurately evaluate the performance of the actual 2.0MW wind turbine, this paper firstly collects the measured wind speed, power and other operational data reflecting the performance of the wind turbine, and analyzes the data according to the standard specification. On the basis of data analysis, this paper obtains the actual power curve of wind turbine, and then compares it with the theoretical power curve. Finally, this paper carries out comparative analysis and performance evaluation of wind turbine operation performance, and propose improvement measures on this basis.

More accurate aeroelastic wind-turbine load simulations using detailed inflow information

In this paper, inflow information is extracted from a measurement database and used for aeroelastic simulations to investigate if using more accurate inflow descriptions improves the accuracy of the simulated fatigue loads. The inflow information is extracted from the nearby met masts and a blade-mounted five-hole pitot tube. The met masts provide measurements of the inflow at fixed positions some distance away, whereas the pitot tube measures the inflow while rotating with the rotor. The met mast measures the free-inflow velocity, but the measured turbulence may evolve on its way to the turbine, pass besides the turbine, or the mast may be in the wake of the turbine. The inflow measured by the pitot tube, on the other hand, is very representative of the wind that acts on the turbine as it is measured close to the blades and includes variations within the rotor plane. This inflow is, however, affected by the presence of the turbine, and therefore an aerodynamic model is used to estimate the free-inflow velocities that would have been at the same time and position without the presence of the turbine. The inflow information used for the simulations includes the mean wind speed and trend, the turbulence intensity, wind shear profile, atmospheric stability dependent turbulence parameters, and azimuthal variations within the rotor plane. In addition, the instantly measured wind speed is used to constrain the turbulence. It is concluded that the period-specific turbulence intensity must be included in the aeroelastic simulations to make the range of the simulated fatigue loads representative for the range of the measured fatigue loads. Furthermore, it is found that the one-to-one correspondence between the measured and simulated fatigue loads is improved considerably by using inflow characteristics extracted from the pitot tube instead of the met-mast-based sensors as input for the simulations. Finally, the use of pitot-tube wind speed to constrain the turbulence is found to decrease the variation of the simulated loads due to different turbulence realisations (seeds), such that the need for multiple simulations is reduced.