Wind Turbulence Intensity Characteristics at 10m Above Ground Along the Cotonou Coast, Benin
Hagninou Elagnon Venance Donnou,
Aristide Barthélémy Akpo,
Julien Djossou,
Basile Bruno Kounouhewa
Issue:
Volume 8, Issue 4, December 2019
Pages:
65-80
Received:
14 October 2019
Accepted:
12 November 2019
Published:
25 November 2019
Abstract: The characteristics of the wind turbulence intensity that are essential to know before installing a wind turbine at a site were investigated along the coast of Cotonou in Benin. The average speed, direction, roughness length, friction velocity, turbulence intensity and relationship between the roughness and wind turbulence intensity were evaluated as well. Using the estimators derived from a simple isotropic Gaussian model of turbulent wind fluctuations, we proposed modified models for estimating the turbulence intensity of wind components. Wind speed and direction data recorded at 10 m above ground level from 2011 to 2014 during the first Compact of the Millennium Challenge Account (MCA) in Benin were utilized. The results obtained indicated that the annual average roughness length is evaluated at 1.25×10-4 m, and the annual mean friction velocity is equal to 0.41 m.s-1. Peak values of the turbulence intensity vary from 0.3 to 0.6 except during the months of January, April, July, August and September. The high values obtained could jeopardize the production of wind energy during these months. The correlation between the turbulence intensity and roughness length ranging from 0.75 in January to 0.94 in August revealed that these two parameters are linked by an increasing linear function. Finally, modified formulations of the longitudinal and transversal wind turbulence intensity developed from the van den Hurk and de Bruin model and based on the best-fitting approach were proposed. The error estimators (MAE; RMSE) computed to validate these modified models vary respectively from (0.0099; 0.0141) to (0.0614; 0.0890).
Abstract: The characteristics of the wind turbulence intensity that are essential to know before installing a wind turbine at a site were investigated along the coast of Cotonou in Benin. The average speed, direction, roughness length, friction velocity, turbulence intensity and relationship between the roughness and wind turbulence intensity were evaluated ...
Show More
The First Discovery of Low-temperature Rhyolite Melts in Cenozoic Long-lived Bazman Volcano, East Iran; Some Problems and Discussion
Alexander Romanko,
Vsevolod Prokof’ev,
Nazim Imamverdiyev,
Vladimir Naumov,
Pavel Plechov,
Anna Balashova,
Bahman Rashidi,
Mehrdad Hedari,
Ilya Vikentev,
Alexander Savichev
Issue:
Volume 8, Issue 4, December 2019
Pages:
81-87
Received:
26 June 2019
Accepted:
4 November 2019
Published:
27 November 2019
Abstract: The igneous rocks, some geological specifics, and also the very melt inclusions in Late Cenozoic rhyolites were studied in the long-lived Miocene (N1, ca. 20 Ma) - Late Quaternary (Q3?) Bazman volcano, eastern Iran. Unusual low temperature (ca. 690o C) silicate melt inclusions in quartz (Qtz) with a High/very High water content (from average 6.9 to 8.2 (up to 9.0 as a limit) wt% H2O) in the acid rocks were defined by independent methods for the first time. Whole-rock chemistry of the melts studied is similar to ones in subduction-related acid melts from different regions. Rhyolites studied sometimes have higher concentration of ore elements, similar to ones in even basites. Ore inheritance from economic porphyry – PCD (Cu-Au +- Mo) Paleogene (mainly Eocene - Pg2) mineralization and deposits in the region is proposed. Geological anomaly of the whole region is proposed by a complex analysis. This anomaly is maybe responsible for anomalous magmatism due to a known tomography data (since Paleocene (Pg1), as minimum), tectonics, metallogeny (including economic one), and maybe - hydrocarbons (HC, oil - gas) activity.
Abstract: The igneous rocks, some geological specifics, and also the very melt inclusions in Late Cenozoic rhyolites were studied in the long-lived Miocene (N1, ca. 20 Ma) - Late Quaternary (Q3?) Bazman volcano, eastern Iran. Unusual low temperature (ca. 690o C) silicate melt inclusions in quartz (Qtz) with a High/very High water content (from average 6.9 to...
Show More
