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Showing 2 results for Shafiei Mayam
Amin Allah Veisi, Mohammad Hossein Shafiei Mayam,
Volume 16, Issue 12 (2-2017)
Abstract
In this study Large Eddy Simulation method has been employed in order to investigate the effects of blade rotation direction of downstream turbine in two co-rotating and counter-rotating configurations. The acquired results are in good agreement with presented experimental data in literatures. Counter-rotating configuration is used in order to investigate the effect of blade rotation on the efficiency of downstream wind turbine. The results show that the efficiency of downstream wind turbine is increased about 4 percent without any change in wind farm layout and type of wind turbines. The upstream wind turbine absorbed a portion of wind energy. Hence stream wise velocity is decreased and lateral velocities are increased in downstream direction. The flow behind the upstream turbine is rotated in same direction with downstream turbine in a counter-rotating configuration. This is why the efficiency of downstream turbine is increased in a counter-rotating configuration. The results of the present study show that streamwise velocity profile is almost identical in both configurations, while, lateral velocities are changed considerably. In other words, a better efficiency of wind farm could be due to the lateral velocities. Hence, the efficiency of wind farm could be increased by decreasing the distance between two consecutive wind turbines in a counter-rotating configuration.
A. Akbarzadeh, M.h. Shafiei Mayam,
Volume 19, Issue 12 (December 2019)
Abstract
In the present work, the effects of blades number on the performance of two stages axial gas turbine have been investigated numerically. Geometry characteristics of the gas turbine have been chosen based on the F5 model of General Electric Company. First, the blades geometry and fluid passages are initially generated due to the real dimensions of the turbine and the generated geometry is networked. Then, the final model of the turbine is generated by gridding blades which set beside each other. Then, Ansys CFX software is used to solve the 3D Navier-Stokes equations in the generated computational domain. The shear stress transport turbulence model has been employed in order to determine the wall effects on the turbulent flow. Before any change in the main turbine, a numerical study was performed and a comparison was conducted between the numerical results and experimental results measured in the power station which the results show a good level of agreement between them. The number of blades of each row has been changed in order to investigate the effects of blade number on the turbine efficiency. The results show that the power generation of the turbine and its efficiency are increased by 0.83% and 0.81%, respectively by an increase in the number of second-row stator blades from 62 to 71 blades.
