scholarly journals Computational analysis of micro wind turbine with bamboo blades for domestic applications

2021 ◽  
Vol 70 (9&10) ◽  
pp. 150
Author(s):  
J. Suraj Sayed ◽  
P. V. Sreeram ◽  
R. Ramesh Kumar

A domestic purpose micro wind turbine realised using bamboo blade is tested for the power generation at an interval of two years and compared the performance. A CFD analysis of turbine with five blade system is carried out for an average wind velocity of 2.5m/s and structural integrity of the bamboo blade unit based on the pressure distribution is assessed. For the input wind velocity, a stream lined out flow of 5.9 m/s is found when wind turbine rotates at 300 rpm and corresponding pressure distribution is found to be maximum at the expected location of blade tip as129 Pa. The static analysis shows a good margin. For 2.5 m/s, a wind turbine generates an average value of 3.8V with 0.25A (based on 15 <span>Ω</span>/10W load). The wind turbine has produced nearly the same power even after a period of two years.

2021 ◽  
Vol 71 (3&4) ◽  
pp. 53
Author(s):  
J. Suraj Sayed ◽  
R. Ramesh Kumar ◽  
P. V. Sreeram

A domestic purpose micro wind turbine realised using bamboo blade is tested for the power generation at an interval of two years and compared the performance. A CFD analysis of turbine with five blade system is carried out for an average wind velocity of 2.5m/s and structural integrity of the bamboo blade unit based on the pressure distribution is assessed. For the input wind velocity, a stream lined out flow of 5.9 m/s is found when wind turbine rotates at 300 rpm and corresponding pressure distribution is found to be maximum at the expected location of blade tip as 129 Pa. The static analysis shows a good margin. For 2.5 m/s, the wind turbine generates an average value of 3.8V with 0.25A (based on 15/10W load). The wind turbine has produced nearly the same power even after a period of two years.


2018 ◽  
Vol 5 (2) ◽  
pp. 70
Author(s):  
Yiyin Klistafani ◽  
Muh Iqbal Mukhsen ◽  
Muh Iqbal Mukhsen

The main objective of numerical simulation in thisstudies is to determine the effect of diffuser’s interior design onincreasing the diffuser augmented wind turbine (DAWT)performance by observing wind velocity increment. Numericalstudies were carried out using the computational Fluid Dynamics(CFD) method through a two-dimensional steady approach withAnsys Fluent 18.2 and Ansys Workbench 18.2 software. Thepresent studies spesifically investigate the shapes of diffuser,namely flat diffuser and curved diffuser. The studies demonstratethat the curved diffuser generates stronger increment of the windvelocity than flat diffuser (at centreline), which 1.842 times thefreestream velocity, while the flat diffuser is only able to increseup to 1.742 times the freestream velocity. The curved diffusershows the highest increment of the average wind velocity alongdiffuser with the greatest increment of 78.66 % and the flatdiffuser is only able to provide average wind velocity incrementup to 44.81%. The curved interor of diffuser is able to enlarge thewake area, so the effect of the suction flow entering the diffuserbecomes stronger. Therefore, curved diffuser is better to provideDAWT performance improvements.


Author(s):  
Sandip Kale ◽  
S. N. Sapali

Micro wind turbines installed in various applications, experience average wind speed for most of the time during operations. Power produced by the wind turbine is proportional to the cubic power of the wind velocity and a small increase in wind velocity results increases power output significantly. The approach wind velocity can be increased by covering traditional wind turbine with a diffuser. Researchers are continuously working to develop a compact, lightweight, cost effective and feasible diffuser for wind turbines. The present work carried out to develop a diffuser with these stated objectives. A compact, lightweight inclined flanged diffuser developed for a micro wind turbine. Bare micro wind turbine and wind turbine covered with developed efficient inclined flanged diffuser tested in the field as per International Electrotechnical Commission (IEC) standards and results presented in the form of power curves. The prediction of annual energy production for both wind turbines determined as per IEC standards.


Author(s):  
Jana Dufková

Wind erosion is caused by meteorological factors such as wind, precipitation and evaporation that influence the soil humidity. Erosive-climatological factor expresses wind and humidity conditions of particular landscape. This is an index of the influence of average soil surface humidity and average wind velocity on average soil erodibility by wind. On the basis of average wind velocity and Konček’s humidity index, the values of the erosive-climatological factor for three chosen areas of Czech republic (Telč-Kostelní Myslová, Znojmo-Kuchařovice and Brno-Tuřany), where the pro-cesses of wind erosion could exist, were evaluated. Thus, the change of the factor’s value during the period of 1961 – 2000 was studied. The linear trend for the region of Brno and Znojmo (dry areas) shows increasing threat of soils by wind erosion, the contrary situation is at the humid area (Telč). The results prove the influence of soil humidity on the erosive-climatological factor and hereby the influence on wind erosion spreadout.


AIMS Energy ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 1147-1169
Author(s):  
Salih Nawaf Akour ◽  
◽  
Mahmoud Azmi Abo Mhaisen

<abstract> <p>Parametric design analysis for Eccentric Rotated Ellipsoid (ERE) shroud profile is conducted whereas the design model is validated experimentally. A relation between shroud inlet, length and exit diameter is established, different ratios related to the wind turbine diameter are introduced, and solution for different ERE family curves that passes on the inlet, throat, and exit points is studied. The performance of the ERE shroud is studied under different wind velocities ranging from 5–10 m/s.</p> <p>The method used in creating the shroud profile is by solving the ERE curve equations to generate large family of solutions. The system is modeled as axisymmetric system utilizing commercial software package. The effect of the parameters; shroud length, exit diameter, inlet diameter, turbine position with respect to the shroud throat, and wind velocity are studied. An optimum case for each shroud length, exit diameter and location of the shroud with respect to the wind turbine throat axis are achieved.</p> <p>The simulation results show an increase in the average wind velocity by 1.63 times of the inlet velocity. This leads to a great improvement in the wind turbine output power by 4.3 times of bare turbine. One of the achieved optimum solutions for the shroud curves has been prototyped for experimental validation. The prototype has been manufactured using 3D printing technology which provides high accuracy in building the exact shape of shroud design curve. The results show very good agreement with the experimental results.</p></abstract>


2001 ◽  
Vol 7 (1) ◽  
pp. 68-72
Author(s):  
Valdas Paukštys ◽  
Vytautas Stankevičius

It is not enough to investigate only the effect of wind on buildings, because deterioration of exterior surfaces of buildings is caused by wind and moisture together. A considerable part of rain gets into the exterior surface of enclosure, penetrates deep down and destroys the material of surface layer. The rain passes through enclosure construction and its surface layer due to wind pressure, through joints of the elements and cracks caused by improper transportation as well as by an inaccurate assembling. At present, new multilayer constructional elements are used for building envelope having numerous assembling seams, therefore, the combined influence of rain and wind becomes rather dangerous. It was established that the wind velocity during the rain is one of the main reasons predetermining moisture penetration into protective-decorative walls made of sand-lime brick with split surface, on concrete-lime mortar, according to the analysis of combined influence of the climate by research data [4]. The total effect of rain and wind on the humidity condition of exterior layers is described. Distribution of real wind velocity was estimated according to the data of the last 10 years. It was found that in Kaunas the average wind velocity increases from 3,4 m/s when the rain is absent up to 4,3 m/s and in Vilnius—the average wind velocity increases from 2,9 m/s when the rain is absent up to 3,7 m/s with an increase of approximately 26%, while in Klaipeda the average wind velocity increases from 3,6 m/s when the rain is absent up to 5,1 m/s with an increase of approximately 42%. On the base of the investigations carried out the suggestion is proposed to use the maximum and mean wind velocity values at the rain for estimating the effect of wind to the moisture behaviour in building elements.


2019 ◽  
Vol 29 (7) ◽  
pp. 1028-1037
Author(s):  
Yijian He ◽  
Xiangyu Chen ◽  
Youming Zheng ◽  
Guangming Chen

Conventional microenvironment control systems of a museum display case generally use mechanical fans which produce great noise and vibration for heat dissipation of semiconductor air-conditioning units. Solid-state fans (ionic wind) operate with no moving parts and can overcome noise and vibration issues of a microenvironment control system. In this study, a multi-electrode mathematical and physical model of wire–plate solid-state fans was developed, and its performance has been analysed in depth. Simulation results indicate that there is an optimal distance between discharge electrodes ( d), which corresponds to the largest average wind velocity at the exit of the simulation area ( ua). Under the same power consumption, ua and the vertical height from a discharge electrode to a collecting electrode ( H) exhibit a monotonically increasing relationship. Similarly, ua and the radius of a discharge electrode ( r) show a monotonically decreasing relationship. In addition, a manufactured solid-state fan with an average wind velocity of 1.48 m·s−1 shows a noise intensity of 4.3 dB(A), which is considerably lower than that of a mechanical fan, with the same power consumption. These positive results suggest that ultra-quiet microenvironment control technologies of a museum display case can be potentially developed in the near future.


2016 ◽  
Vol 8 (4) ◽  
pp. 183
Author(s):  
Krzysztof Borowski

<p>The influence of the weather on human behavior have been featured in many, not only scientific publications.  This paper tests the hypothesis that the one-session average rates of return of equity indices (WIG, WIG20, mWIG40 and sWIG80) calculated for the different weather conditions differ in two populations. The atmospheric conditions taken into consideration in this paper are as follows: maximum and minimum daily temperature, sunny hours, rainfall, maximum and average wind velocity, atmospheric pressure, snow depth, sun energy ultraviolet radiation index. In the analyzed period, the impact on the daily rates of return was observed in the case of the following weather conditions: maximum daily temperature, sunny hours, rainfall, maximum wind velocity and atmospheric pressure. The other analyzed weather conditions such as average wind velocity, minimum daily temperature, snow depth, sun energy ultraviolet radiation index, turned out to be irrelevant. Thus, the influence of some weather condition on registered rates of return on the Polish equity markets has been proved.</p>


Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3199
Author(s):  
Zhengrong Jiang ◽  
Weijun Gao

A comfortable wind environment favors the sustainable development of urban residential districts and public health. However, the rapid growth of high-rise urban residential districts leads to low wind velocity environments in summer. This study examines the influence of enclosure boundary patterns and lift-up design on the wind environment and proposes an optimization strategy to improve the low wind velocity environment in residential districts in summer. A typical residential district in Hangzhou was selected; the average wind velocity, calm wind zone ratio and comfortable wind zone ratio were selected as the evaluation indexes. The wind environment for different enclosure boundary patterns and lift-up designs were obtained via computational fluid dynamics (CFD) simulations. The results indicate that the pedestrian wind environment is greatly improved in residential districts by reducing the height/width of the enclosure boundary, increasing the permeability rate and adopting a lift-up design in all buildings within residential districts. A combination of permeable railings and lift-up design is recommended; this can increase the average wind velocity and the ratio of comfortable wind zones by 70% and 200%, respectively. This study provides practical guidelines for the optimization of a low wind velocity environment in Chinese high-density residential districts in summer.


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