Maduako Emmanuel Okorie

The Namibia University of Science and Technology · Department of Mechanical Engineering

Instrumented towers used for wind measurement are in the region of the atmosphere where atmospheric turbulence is expected to dominate the flow regime. Error readings captured by the speed sensors as a result of tower shadowing are expected to increase due to atmospheric turbulence. Although the understanding is that tower shadowing should be consi...

The controlling parameters (thrust coefficient () and the tower leg lengths ()) found in the centreline speed deficit expression provided in the International Electrotechnical Commission (IEC 61400-12-1) standard which derivation was based on the reference direction (=°) are angle dependent. It is therefore crucial to evaluate and incorporate value...

The boom length obtained from the International Electro technical Commission (IEC 61400-12-1) standard is based on the centreline velocity deficit expression derived on the assumed incident wind that is perpendicular to the tower face, giving rise to a velocity deficit value that is predicted using the upstream contour profile of the modified flow...

Literature on the evaluation methods for tower wake distortion effect based on the wind measurement is reviewed, including 50 peer reviewed journal articles, conference papers, standards, thesis and reports published between 1941 and 2019. A review of the literatures published prior to 2005 sets the foundation for a critical review of the Internati...

The wind characteristics and wind speed profile of Lüderitz, a coastal town of Namibia, were statistically analysed through the application of a two parameter Weibull Probability Distribution Function method to wind data measurements collected over one year at different heights using a dedicated tubular mast. At a hub height of 45.96m, the annual v...

Accurate identification and definition of tower wake boundaries for wind measurement is crucial for site representative wind characterization and economic evaluation. Besides computational and wind tunnel approaches, other methods utilized in field experiments to identify tower waked direction sectors are traditional speed ratio and the coefficient...

The transport industry is one of the highest consumers of aluminium alloys. However, the quest for new and cheaper aluminium with properties comparable to the contenders has remain in the research domain for sometimes. Even at that, the literature is dearth of clear ideas on conversion of the huge RBCs to X7475 experimental alloys. In furtheranc...

Wind shear coefficients and roughness lengths over inland locations in southern Namibia were evaluated. Ten-minute average wind data collected at Korabib and Warmbad over a one year period were utilized. Mean values of wind shear coefficients are 0.197 and 0.132 and the roughness lengths are 0.187 and 0.017 m at Korabib and Warmbad respectively. Ex...

In this study the extent of tower and boom wake distortions were evaluated using collocated anemometers and Lidar measurement based on wind data from Amperbo, Namibia, where an existing latticed equilateral triangular communication tower was instrumented according to IEC specifications. Wind data analysed was 10-minute averaged, captured over a per...

In this present work, 10 minutes averaged concurrently measured wind data using collocated anemometers at 16.88 m height and Light Detecting and Ranging (LIDAR) at 16 m height, collected over a period of one month (June 1-June 30, 2014), have been analyzed to identify the tower wake distortion. lattice equilateral triangular communication towers wi...

In this present work, 10 minutes averaged concurrently measured wind data using collocated anemometers at 16.88 m height and Light Detecting and Ranging (LIDAR) at 16 m height, collected over a period of one month (June 1-June 30, 2014), have been analyzed to identify the tower wake distortion. lattice equilateral triangular communication towers wi...

This paper reviews the sustainability metrics (feasibility, viability, desirability) of renewable energy in the drive for sustainable industrialization and economic development in sub-Saharan Africa (SSA). The tools used were Geographical Information System (GIS) combined with Multi-criteria Decision Making (MCDM) in relation to the framework of Mu...

Wind shear coefficient (WSC) analysis and energy yield estimation were performed at a coastal and an inland location in Namibia using 10-minute average wind speeds collected at the two locations over a period of one year (January to December 2013). To enable proper understanding of wind shear trends, WSCs, and roughness lengths, wind data were obse...

Wind shear coefficients and roughness lengths over inland locations in southern Namibia were evaluated. Ten-minute average wind data collected at Korabib and Warmbad over a one year period were utilized. Mean values of wind shear coefficients are 0.197 and 0.132 and the roughness lengths are 0.187 and 0.017 m at Korabib and Warmbad respectively. Ex...