scholarly journals THE IMPACT OF LONG CANYON DESIGN AND WATERFRONT BARRIER BUILDINGS ON WIND VELOCITY IN A COASTAL AREA OF SELATPANJANG CITY

Arsitektura ◽  
2018 ◽  
Vol 16 (2) ◽  
pp. 231 ◽  
Author(s):  
Boby Rahman ◽  
Asri Dinapradipta ◽  
Ima Defiana

<p class="Abstract"><em>The increase of waterfront buildings’ height has an effect on wind distribution in the urban canyon. On the other hand, the distribution of wind is needed in providing thermal balance in urban environments, especially in urban waterfront coastal areas. This study aimed at observing and analyzing the effect of building height (H) on waterfront buildings and aspects of the length to width (L/W) ratio related to the length of the canyon design. The observation was focused on the wind speed distribution. The research was an experimental research using ENVI-met V3.1 software for simulation. The results indicated that short canyon (low L/W value) results in lower wind speed changes compared to that of long one (higher L/W value) at all altitude levels. The short canyons provided more stability in wind speed reduction. The 15 meters wide of canyon design contributed to the highest average wind speed. Overall, the existence of a barrier building would result in a negative area of air flow and create a calm area within the distance of  ± 50 meters.</em></p><em></em>

2013 ◽  
Vol 1 (1) ◽  
pp. 10-15
Author(s):  
Kamaruzzaman Sopian ◽  
Tamer Khatib

 In this paper, the wind energy potential in Malaysia is examined by analyzing hourly wind speed data for nine coastal sites namely Bintulu, Kota Kinabalu, Kuala Terengganu, Kuching, Kudat, Mersing, Sandakan, Tawau and Pulau Langkawi. The monthly averages of wind speed and wind energy are calculated. Moreover, the wind speed distribution histogram is constructed for these sites. The results showed that the average wind speed for these sites is in the range of (1.8-2.9) m/s while the annual energy of the wind hitting a wind turbine with a 1 m2 swept area is in the range of (15.4-25.2) kWh/m2.annum. This paper provides a data bank for wind energy for Malaysia.


2013 ◽  
Vol 1 (1) ◽  
pp. 10-15
Author(s):  
Kamaruzzaman Sopian ◽  
Tamer Khatib

 In this paper, the wind energy potential in Malaysia is examined by analyzing hourly wind speed data for nine coastal sites namely Bintulu, Kota Kinabalu, Kuala Terengganu, Kuching, Kudat, Mersing, Sandakan, Tawau and Pulau Langkawi. The monthly averages of wind speed and wind energy are calculated. Moreover, the wind speed distribution histogram is constructed for these sites. The results showed that the average wind speed for these sites is in the range of (1.8-2.9) m/s while the annual energy of the wind hitting a wind turbine with a 1 m2 swept area is in the range of (15.4-25.2) kWh/m2.annum. This paper provides a data bank for wind energy for Malaysia.


Energies ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 3048 ◽  
Author(s):  
Telesca ◽  
Guignard ◽  
Helbig ◽  
Kanevski

The 10-min average wind speed series recorded at 130 stations distributed rather homogeneously in the territory of Switzerland are investigated. Fixing a percentile-based threshold of the wind speed distribution, a wind extreme is defined as the duration of the sequence of consecutive wind values above the threshold. This definition allows to analyze the sequence of extremes as a temporal point process marked by their duration. Representing the sequence of wind extremes by the inter-extreme interval series, the wavelet variance, a useful tool to investigate the variance of a time series across scales, was applied in order to find a link between the wavelet scales and several topographic parameters. Our findings suggest that the mean duration of wind extremes and mean inter-extreme time are positively correlated and that such relationship depends on the threshold of the wind speed. Furthermore, the threshold of the wind speed distribution correlates best with a terrain parameter related to the Laplacian of terrain elevations; and, in particular, for wavelet scales less than 3, the terrain exposure may explain the formation of extreme wind speeds.


2018 ◽  
Vol 16 (2) ◽  
pp. 153-157
Author(s):  
Atanas Atanasov ◽  
Tanya Pehlivanova

The article presents the results of wind potential research in the area of Faculty of Technics and Technologies of Yambol, Trakia University of Stara Zagora, Bulgaria. Measurements were made in the period from 01.06.2017 to 27.11.2017. For both seasons - summer and autumn the average wind speed and wind speed distribution are determined. The wind roses, which give a visual idea of the distribution of wind potential in different directions are build. Conclusions for the possibility of using the wind potential for extracting electricity are made.


2021 ◽  
pp. 1-6
Author(s):  
Noreen M. Mutoro ◽  
Jonas Eberle ◽  
Jana S. Petermann ◽  
Gertrud Schaab ◽  
Mary Wykstra ◽  
...  

Abstract Knowledge on cheetah population densities across their current range is limited. Therefore, new and efficient assessment tools are needed to gain more knowledge on species distribution, ecology and behaviour. Scat detection dogs have emerged as an efficient and non-invasive method to monitor elusive and vulnerable animal species, like cheetahs, due to the dog’s superior olfactory system. However, the success of locating scat using detection dogs can be significantly improved under suitable weather conditions. We examined the impact of temperature, humidity and wind speed on detection rates of scat from cheetahs during a scat detection dog survey in Northern Kenya. We found that average wind speed positively influences the scat detection rate of detection dogs working on leash. Humidity showed no significant influence. Temperature showed a strong negative correlation with humidity and thus was excluded from our model analyses. While it is likely that wind speed is especially invalid for dogs working off leash, this study did not demonstrate this. Wind speed could thus influence the success of monitoring cheetahs or other target species. Our findings help to improve the survey and thus maximise the coverage of study area and the collection of target samples of elusive and rare species.


2018 ◽  
Vol 173 ◽  
pp. 01028
Author(s):  
Xiao Yu ◽  
Guofei Lu ◽  
Wuhui Chen ◽  
Danhui Wang

The existing method for investigating the subsynchronous resonance (SSR) caused by wind powergeneration is mainly aimed at a deterministic condition. In order to analyse the impact of uncertain factors onSSR in wind farms, this paper defines the risk matrix and risk index, and develops a SSR-oriented riskassessment method of using probabilistic collocation method (PCM). Considering the uncertain of windspeeds, the proposed method is used to assess the SSR risk of a wind farm. The results show that under thesame wind speed distribution, the higher the series compensation level in the system is, the greater the SSRrisk of the system could be; under the same series compensation level, the SSR risks caused by different windspeed distribution are different, and the system in the areas with lower average wind speed obtains greater SSR risk.


Author(s):  
Tomáš Středa ◽  
Petra Malenová ◽  
Hana Pokladníková ◽  
Jaroslav Rožnovský

Windbreaks have been used for many years to reduce wind speed as a wind-erosion control mea­su­re. To assessment of windbreak efficiency two main parameters are using: height of windbreak (H) and aerodynamic porosity. In South Moravian Region the total area of windbreaks is approximately 1200 ha. For purposes of horizontal profile measurement of wind speed and wind direction windbreaks with various spices composition, age and construction in cadastral territory Suchá Loz and Micmanice were chosen. Windbreak influence on horizontal wind profile was found out in distance of 50, 100, 150 and 200 m in front and behind windbreak in two-meter height above surface. For the optical porosity measurement the ImageTool program was used. The wind field measurement results of windbreak in Suchá Loz cadastral shows limited effect of windbreak on wind speed. The windbreak is created mainly by Canadian poplars (Populus × canadensis). In dependence on main species foliage stage the effect of windbreak was obvious on leeward side to distance of 100–150 m (c. 5–7 H). Average optical porosity of windbreak in Suchá Loz was 50% (April). Reduction of average wind speed was about 17% maximally in this stage. Optical porosity was 20% and wind speed reduction was about 37% during second measurement (October). The second monitored windbreak (Micmanice) had a significant influence on wind speed even to the maximal measured distance (200 m, c. 14 H). This windbreak crea­ted mainly by Acer sp. and Fraxinus excelsior reduced the wind speed about 64%. During first measurement (May) the optical porosity of 20% and maximal wind speed reduction of 64% were assessed. For optical porosity of 21% (October) the wind speed reduction was about 55%. Close relation between optical porosity and wind speed reduction was found out by statistical evaluation. Correlation coefficient regardless locality for distance of 50 m was −0.80, 100 m −0.92, 150 m −0.76 and for distance of 200 m −0.63.


Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3063 ◽  
Author(s):  
Krishnamoorthy R ◽  
Udhayakumar K ◽  
Kannadasan Raju ◽  
Rajvikram Madurai Elavarasan ◽  
Lucian Mihet-Popa

Wind energy is one of the supremely renewable energy sources and has been widely established worldwide. Due to strong seasonal variations in the wind resource, accurate predictions of wind resource assessment and appropriate wind speed distribution models (for any location) are the significant facets for planning and commissioning wind farms. In this work, the wind characteristics and wind potential assessment of onshore, offshore, and nearshore locations of India—particularly Kayathar in Tamilnadu, the Gulf of Khambhat, and Jafrabad in Gujarat—are statistically analyzed with wind distribution methods. Further, the resource assessments are carried out using Weibull, Rayleigh, gamma, Nakagami, generalized extreme value (GEV), lognormal, inverse Gaussian, Rician, Birnbaum–Sandras, and Bimodal–Weibull distribution methods. Additionally, the advent of artificial intelligence and soft computing techniques with the moth flame optimization (MFO) method leads to superior results in solving complex problems and parameter estimations. The data analytics are carried out in the MATLAB platform, with in-house coding developed for MFO parameters estimated through optimization and other wind distribution parameters using the maximum likelihood method. The observed outcomes show that the MFO method performed well on parameter estimation. Correspondingly, wind power generation was shown to peak at the South West Monsoon periods from June to September, with mean wind speeds ranging from 9 to 12 m/s. Furthermore, the wind speed distribution method of mixed Weibull, Nakagami, and Rician methods performed well in calculating potential assessments for the targeted locations. Likewise, the Gulf of Khambhat (offshore) area has steady wind speeds ranging from 7 to 10 m/s with less turbulence intensity and the highest wind power density of 431 watts/m2. The proposed optimization method proves its potential for accurate assessment of Indian wind conditions in selected locations.


2011 ◽  
Vol 55-57 ◽  
pp. 849-852
Author(s):  
Zhao Kun Wang ◽  
Jun Yi ◽  
Ming Yong Lai ◽  
Bao Ping Liu

In this paper the model of Copula-based security assessment of power insulators under the impact of the storm is proposed. The model firstly analysis the daily average winds speed, the historical daily rainfall data to get the probability of wind speed and daily rainfall distribution. Then presents the model of security assessment of power insulators under the impact of wind and rainfall by considering not only the probability of relevance between the daily average wind speed and daily rainfall by using Copula join function, but also the combination of meteorological factors on the impact of power insulators security. This work was supported by the Key Scientific and Technological Project of Hunan Province of China (2008FJ1006).


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