Performance analysis of a harmonica-type aeroelastic micropower generator

2012 ◽  
Vol 23 (13) ◽  
pp. 1461-1474 ◽  
Author(s):  
Amin Bibo ◽  
Gang Li ◽  
Mohammed F Daqaq
Keyword(s):  
Wind Speed ◽  
Output Power ◽  
Design Parameters ◽  
Average Wind Speed ◽  
Chamber Volume ◽  
Average Wind ◽  
Proposed Model ◽  
Basic Physics ◽  
Aperture Width ◽  
Micropower Generator

This article investigates the influence of the design parameters on the performance of an aeroelastic micropower generator with the goal of minimizing its cut-in wind speed and maximizing its output power. The generator, which mimics the basic physics of music-playing harmonicas, transforms wind energy into electricity via the self-excited oscillations of a piezoelectric reed embedded within a cavity. Previously, the authors have presented and validated an analytical aeroelectromechanical model describing the response behavior of the generator. By utilizing the proposed model, this study implements a stability analysis and numerical optimization algorithms to delineate the influence of the design parameters on the device’s response. The effect of the electric load, chamber volume, and aperture size on the cut-in wind speed is investigated. The results illustrate that the cut-in wind speed can be reduced significantly if the device is designed with an optimal chamber volume, which is shown to be inversely proportional to the square of the beam’s first modal frequency. Minimizing the aperture width is also shown to significantly reduce the cut-in speed. However, due to the reduced strain rate in the piezoelectric layer, it is observed that minimizing the wind speed does not always yield an increase in the output power. As such, a numerical investigation of the influence of the design parameters on the output power is utilized to generate design charts that assist in the selection of the optimal parameters for a known average wind speed. Several qualitative verifications of the theoretical trends are also presented through an experimental case study.

Design Considerations for an Aeroelastic Micro-Power Generator

2011 ◽  
Author(s):  
Amin Bibo ◽  
Gang Li ◽  
Mohammed F. Daqaq
Keyword(s):  
Wind Speed ◽  
Output Power ◽  
Numerical Algorithms ◽  
Design Parameters ◽  
Modeling Framework ◽  
Average Wind Speed ◽  
Power Generator ◽  
Chamber Volume ◽  
Micro Power ◽  
Micro Power Generator

In two recent studies [1; 2], the authors have presented the concept and the analytical modeling framework for a scalable wind micro-power generator. The device transforms wind energy into electricity via the self-excited oscillations of a piezoelectric reed embedded within a cavity. Based on the model developed in [2], this effort utilizes the Routh-Hurwitz criterion and numerical algorithms to understand the influence of the design parameters on the device’s response with the goal of minimizing the cut-on wind speed and maximizing the output power. Results indicate that, for a beam of certain design parameters, there exists an optimal chamber volume that minimizes the cut-on wind speed of the device. This optimal volume is inversely proportional to the beam’s first modal frequency. Results also indicate that the cut-on wind speed can be decreased significantly as the aperture’s width is decreased. However, due to the reduced strain rate in the piezoelectric layer, it is observed that minimizing the cut-on wind speed does not always correspond to an increase in the output power. As such, in an attempt to study the influence of the design parameters on the output power, design charts were constructed to select the optimal design parameters for a known average wind speed. Experimental results are also presented to qualitatively verify the theoretical trends.

scholarly journals ANALISIS PEMBANGKIT LISTRIK MENGGUNAKAN TURBIN ANGIN SAVONIUS

2020 ◽  
pp. 31-38
Author(s):  
Sudirman S ◽  
Sri Kurniati, A ◽  
M. Ikram A. Arifin
Keyword(s):  
Wind Speed ◽  
Output Power ◽  
Wind Turbines ◽  
Vertical Shaft ◽  
Simple Construction ◽  
Main Rotor ◽  
Average Wind Speed ◽  
Average Wind ◽  
Average Rotation ◽  
Load Conditions

ABSTRAK Turbin angin tipe Savonius adalah salah satu turbin angin poros vertikal (VAWT) dengan konstruksi sederhana yang memiliki rotor utama berputar secara vertikal. Kelebihannya adalah dapat memanfaatkan angin dari segala arah, mampu bekerja dengan kecepatan rendah, serta ia tidak membutuhkan menara yang terlalu tinggi. Tujuan dari penelitian ini adalah untuk menganalisis kinerja turbin berdasarkan rotasi dan output generator beban. Metode yang digunakan adalah melakukan pengukuran langsung putaran turbin dan generator dalam kondisi tanpa beban dan kondisi muatan. Hasil penelitian diperoleh  kecepatan angin rata-rata di desa Oenali adalah 4,64 m/s, dan turbin ini yang mampu memutar turbin Savonius dengan putaran rata-rata 631 rpm. Kemudian, pada putaran generator 1.243 rpm mampu menghasilkan daya output sebesar 7,20 watt. Selain itu, efisiensi generator rata-rata sebesar 36%, efisiensi harian tertinggi adalah 38%, dan efisiensi harian terendah adalah 35%   ABSTRACT Savonius type wind turbines are one of the vertical shaft wind turbines (VAWT) with a simple construction that has a vertically rotating main rotor. The advantage is that it can take advantage of the wind from all directions, is able to work at low speeds, and it does not need a tower that is too high. The purpose of this study is to analyze the performance of the turbine based on the rotation and output of the load generator. The method used is to measure directly the rotation of the turbine and generator under no-load and load conditions. The results showed an average wind speed in Oenali village was 4.64 m / s, and this turbine was able to rotate Savonius turbines with an average rotation of 631 rpm. Then, the generator speed of 1,243 rpm can produce an output power of 7.20 watts. In addition, the average generator efficiency is 36%, the highest daily efficiency is 38%, and the lowest daily efficiency is 35%.

A practical seasonal performance evaluation of small wind turbine in urban environment

2019 ◽  
Vol 43 (4) ◽  
pp. 344-358
Author(s):  
Zakariya Rajab ◽  
Yousef sassi ◽  
Ahmed Taher ◽  
Asharf Khalil ◽  
Faisal Mohamed
Keyword(s):  
Performance Evaluation ◽  
Wind Speed ◽  
Wind Turbine ◽  
Urban Environment ◽  
Output Power ◽  
Energy Production ◽  
Average Wind Speed ◽  
Average Wind ◽  
Small Wind Turbines ◽  
Seasonal Performance

Due to the low environmental impact, smaller storage units, low wind speed, low power system distribution network impact, and low maintenance, small wind turbines have gained more attention. However, the usage of small turbines usually faces several shortcomings, and the actual yield is often lower than expected, generally because the output power is low when compared with the manufacturer, and the actual wind turbine behavior does not reproduces. In a view of performance evaluation of a small wind turbines using high-accuracy measurement devices to measure wind speed and energy production, this article illustrates an experimental seasonal performance evaluation of a 0.5-kW Hummer small wind turbine, placed in an urban environment. In addition, we study the influence of the height in the energy output and analyze its effect in the system performance, which is another aim in this work. Three cases have been carried out: 4 m in order to protect rotor blades during strong winds and storms in the first scenario and 6 m the manufacturing height in the second scenario while 10 m the third case. A 0.5-kW Hummer wind turbine has been installed in Noagia-Benghazi since 2010 for educational purposes, field studies, training, graduate projects, and research. The wind turbine seasonal performance under different periods was obtained and compared in terms of the wind speed, output power, energy production, and average wind speed. The average wind speed is 6.4, 4, 5.8, and 4 m/s, and the average energy production is 948.24, 172.8, 648, and 172.8 kWh in spring, summer, winter, and autumn, respectively. Spring has the highest wind speed followed by winter and autumn then summer for all height. Improvement is attained if the wind turbine tower height is 6 m, and 10 m where more energy is harvested. But the main problem at 10 m is that the system control needs more improvement because the wind speed exceeds 14 m/s which represents the maximum speed. The system can produce about 1.942 MW yearly and save CO2 emissions.

SHAPING OF AN AUTONOMOUS POWER SYSTEM FOR GUARANTEED POWER SUPPLY WITH THE PREDOMINANCE WIND ENERGY

2018 ◽  
pp. 28-50
Author(s):  
S. G. Ignatiev ◽  
S. V. Kiseleva
Keyword(s):  
Energy Storage ◽  
Wind Speed ◽  
Wind Energy ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Energy Demand ◽  
Diesel Generator ◽  
Average Wind Speed ◽  
Wind Speeds ◽  
Average Wind

Optimization of the autonomous wind-diesel plants composition and of their power for guaranteed energy supply, despite the long history of research, the diversity of approaches and methods, is an urgent problem. In this paper, a detailed analysis of the wind energy characteristics is proposed to shape an autonomous power system for a guaranteed power supply with predominance wind energy. The analysis was carried out on the basis of wind speed measurements in the south of the European part of Russia during 8 months at different heights with a discreteness of 10 minutes. As a result, we have obtained a sequence of average daily wind speeds and the sequences constructed by arbitrary variations in the distribution of average daily wind speeds in this interval. These sequences have been used to calculate energy balances in systems (wind turbines + diesel generator + consumer with constant and limited daily energy demand) and (wind turbines + diesel generator + consumer with constant and limited daily energy demand + energy storage). In order to maximize the use of wind energy, the wind turbine integrally for the period in question is assumed to produce the required amount of energy. For the generality of consideration, we have introduced the relative values of the required energy, relative energy produced by the wind turbine and the diesel generator and relative storage capacity by normalizing them to the swept area of the wind wheel. The paper shows the effect of the average wind speed over the period on the energy characteristics of the system (wind turbine + diesel generator + consumer). It was found that the wind turbine energy produced, wind turbine energy used by the consumer, fuel consumption, and fuel economy depend (close to cubic dependence) upon the specified average wind speed. It was found that, for the same system with a limited amount of required energy and high average wind speed over the period, the wind turbines with lower generator power and smaller wind wheel radius use wind energy more efficiently than the wind turbines with higher generator power and larger wind wheel radius at less average wind speed. For the system (wind turbine + diesel generator + energy storage + consumer) with increasing average speed for a given amount of energy required, which in general is covered by the energy production of wind turbines for the period, the maximum size capacity of the storage device decreases. With decreasing the energy storage capacity, the influence of the random nature of the change in wind speed decreases, and at some values of the relative capacity, it can be neglected.

scholarly journals Analysis of Performance of the Wind-Driven Pulverizing Aerator Based on Average Wind Speeds in the Conditions of Góreckie Lake

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2796
Author(s):  
Andrzej Osuch ◽  
Ewa Osuch ◽  
Stanisław Podsiadłowski ◽  
Piotr Rybacki
Keyword(s):  
Mathematical Model ◽  
Wind Speed ◽  
Water Pump ◽  
Average Wind Speed ◽  
Flow Rates ◽  
Wind Speeds ◽  
Average Wind ◽  
Flow Through ◽  
Analysis Of Performance ◽  
Research Period

In the introduction to this paper, the characteristics of Góreckie lake and the construction and operation of the wind-driven pulverizing aerator are presented. The purpose of this manuscript is to determine the efficiency of the pulverizing aerator unit in the windy conditions of Góreckie Lake. The efficiency of the pulverization aerator depends on the wind conditions at the lake. It was necessary to conduct thorough research to determine the efficiency of water flow through the pulverization segment (water pump). It was necessary to determine the rotational speed of the paddle wheel, which depended on the average wind speed. Throughout the research period, measurements of hourly average wind speed were carried out. It was possible to determine the efficiency of the machine by developing a dedicated mathematical model. The latest method was used in the research, consisting of determining the theoretical volumetric flow rates of water in the pulverizing aerator unit, based on average hourly wind speeds. Pulverization efficiency under the conditions of Góreckie Lake was determined based on 6600 average wind speeds for spring, summer and autumn, 2018. Based on the model, the theoretical efficiency of the machine was calculated, which, under the conditions of Góreckie Lake, amounted to 75,000 m3 per year.

scholarly journals Formation and distribution of sea-surface microlayers

2010 ◽  
Vol 7 (4) ◽  
pp. 5719-5755 ◽  
Author(s):  
O. Wurl ◽  
E. Wurl ◽  
L. Miller ◽  
K. Johnson ◽  
S. Vagle
Keyword(s):  
Wind Speed ◽  
Primary Production ◽  
Sea Surface ◽  
Surface Microlayer ◽  
Average Wind Speed ◽  
Wind Speeds ◽  
Average Wind ◽  
The Pacific ◽  
Sea Surface Microlayer ◽  
Natural Surfactants

Abstract. Results from a study of surfactants in the sea-surface microlayer (SML) in different regions of the ocean (subtropical, temperate, polar) suggest that this interfacial layer between the ocean and atmosphere covers the ocean's surface to a significant extent. Threshold values at which primary production acts as a significant source of natural surfactants have been derived from the enrichment of surfactants in the SML relative to underlying water and local primary production. Similarly, we have also derived a wind speed threshold at which the SML is disrupted. The results suggest that surfactant enrichment in the SML is typically greater in oligotrophic regions of the ocean than in more productive waters. Furthermore, the enrichment of surfactants persisted at wind speeds of up to 10 m s−1 without any observed depletion above 5 m s−1. This suggests that the SML is stable enough to exist even at the global average wind speed of 6.6 m s−1. Global maps of primary production and wind speed are used to estimate the ocean's SML coverage. The maps indicate that wide regions of the Pacific and Atlantic Oceans between 30° N and 30° S are more significantly affected by the SML than northern of 30° N and southern of 30° S due to higher productivity (spring/summer blooms) and wind speeds exceeding 12 m s−1 respectively.

scholarly journals Remaining Useful Life Estimation of Wind Turbine Blades under Variable Wind Speed Conditions Using Particle Filters

2018 ◽  
Vol 10 (1) ◽  
Author(s):  
Bhavana Valeti ◽  
Shamim N. Pakzad
Keyword(s):  
Wind Speed ◽  
Wind Turbine ◽  
Turbine Blades ◽  
Remaining Useful Life ◽  
Structural Components ◽  
Wind Turbine Blades ◽  
Average Wind Speed ◽  
Average Wind ◽  
Useful Life ◽  
Variable Wind

Rotor blades are the most complex structural components in a wind turbine and are subjected to continuous cyclic loads of wind and self-weight variation. The structural maintenance operations in wind farms are moving towards condition based maintenance (CBM) to avoid premature failures. For this, damage prognosis with remaining useful life (RUL) estimation in wind turbine blades is necessary. Wind speed variation plays an important role influencing the loading and consequently the RUL of the structural components. This study investigates the effect of variable wind speed between the cutin and cut-out speeds of a typical wind farm on the RUL of a damage detected wind turbine blade as opposed to average wind speed assumption. RUL of wind turbine blades are estimated for different initial crack sizes using particle filtering method which forecasts the evolution of fatigue crack addressing the non-linearity and uncertainty in crack propagation. The stresses on a numerically simulated life size onshore wind turbine blade subjected to the above wind speed loading cases are used in computing the crack propagation observation data for particle filters. The effects of variable wind speed on the damage propagation rates and RUL in comparison to those at an average wind speed condition are studied and discussed.

scholarly journals The super-turbine wind power conversion paradox: using machine learning to reduce errors caused by Jensen's inequality

2019 ◽  
Vol 4 (2) ◽  
pp. 343-353 ◽  
Author(s):  
Tyler C. McCandless ◽  
Sue Ellen Haupt
Keyword(s):  
Machine Learning ◽  
Standard Deviation ◽  
Wind Speed ◽  
Wind Power ◽  
Power Conversion ◽  
Jensen’S Inequality ◽  
Jensen's Inequality ◽  
Average Wind Speed ◽  
Wind Speeds ◽  
Average Wind

Abstract. Wind power is a variable generation resource and therefore requires accurate forecasts to enable integration into the electric grid. Generally, the wind speed is forecast for a wind plant and the forecasted wind speed is converted to power to provide an estimate of the expected generating capacity of the plant. The average wind speed forecast for the plant is a function of the underlying meteorological phenomena being predicted; however, the wind speed for each turbine at the farm is also a function of the local terrain and the array orientation. Conversion algorithms that assume an average wind speed for the plant, i.e., the super-turbine power conversion, assume that the effects of the local terrain and array orientation are insignificant in producing variability in the wind speeds across the turbines at the farm. Here, we quantify the differences in converting wind speed to power at the turbine level compared with a super-turbine power conversion for a hypothetical wind farm of 100 2 MW turbines as well as from empirical data. The simulations with simulated turbines show a maximum difference of approximately 3 % at 11 m s−1 with a 1 m s−1 standard deviation of wind speeds and 8 % at 11 m s−1 with a 2 m s−1 standard deviation of wind speeds as a consequence of Jensen's inequality. The empirical analysis shows similar results with mean differences between converted wind speed to power and measured power of approximately 68 kW per 2 MW turbine. However, using a random forest machine learning method to convert to power reduces the error in the wind speed to power conversion when given the predictors that quantify the differences due to Jensen's inequality. These significant differences can lead to wind power forecasters overestimating the wind generation when utilizing a super-turbine power conversion for high wind speeds, and indicate that power conversion is more accurately done at the turbine level if no other compensatory mechanism is used to account for Jensen's inequality.

Estimation of average wind speed in the city of Tianguá using Artificial Neural Network

2021 ◽  
Author(s):  
Arilson F. G. Ferreira ◽  
Anderson P. de Aragao ◽  
Necio de L. Veras ◽  
Ricardo A. L. Rabelo ◽  
Petar Solic
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Wind Speed ◽  
Average Wind Speed ◽  
Average Wind ◽  
Artificial Neural ◽  
The City
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