Effect of fluctuated flow on horizontal axis wind turbines at various tip speed ratios

• Main Authors: Aljuhashy, Radwan M., Hamdoon, Farouk Omar, Al-Bakri, Basim A. R., Firdaus, Ahmad Riyad, Howell, Robert J.
• Format: Conference Proceeding
• Language: English
• Subjects: Equilibrium flow; Horizontal Axis Wind Turbines; Mathematical models; Ratios; Steady flow; Steady state; Tip speed; Turbines; Unsteady flow; Wind effects
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/5.0126005

The value of tip speed ratio (TSR or λ) of a wind turbine was evaluated numerically in this study. A wind turbine of NREL VI model and the test section of NASA/Ames tunnel was chosen in this study by using a CFD package, ANSYS Fluent 19.1. In general, the power coefficient was determined at different tip speed ratios. It was maximum (0.424 and 0.268) for steady flow state at TSR= 6 for the real and small-size respectively. For unsteady flow, it was (0.401 and 0.168) at TSR= 6 for the real and small-size respectively. The effect of unsteady wind flow in wind turbines was studied then compared with that of steady-state conditions flow. Moreover, for real and small-size turbines, the study included the tip speed ratios at (lower and higher values than the design one) which were 4 and 8 for this type of wind turbine. Generally, the trend of the small-size wind turbine performance showed a high similarity with its full scale corresponding numerical result. Moreover, the average unsteady flow performance at λ =6 was lower than that of the steady-state flow curve. However, it was high relatively at others tip speed ratios.