Akademik Veri Yönetim Sistemi
AIAA Aviation Forum and ASCEND, 2024, Nevada, Amerika Birleşik Devletleri, 29 Temmuz - 02 Ağustos 2024
In this study, a virtual roughness element was employed on the blades of a H-type Darrieus vertical axis wind turbine (VAWT) with NACA0018 blades and its effect on turbine performance was investigated. The optimum length of the roughness device and its location on the blade are presented with 2D analysis. The roughness heights depending on the chord length were investigated as k/c: 0.003, 0.006, 0.009, 0.012 and chordwise roughness ratios on the surface are 5%, 10%, and 50%. Time-dependent torque changes were obtained via ANSYS Fluent 18.2 software, therefore the variation of power coefficient over the time was evaluated taking into consideration tip speed ratio. The results of x velocity component and turbulence kinetic energy distributions in different x/c and k/c dimensionless parameters were compared in terms of examining their effects on turbine aerodynamics. Numerical results showed that the best power coefficient values were achieved at chordwise roughness ratio on the surface: 50% (x/c: 0-0.50). Since the highest efficiency was achieved at this x/c: 0-0.50 value, this x/c range was highlighted in terms of roughness height. As the roughness ratios k/c: 0.003, 0.006, 0.009, and 0.012 were analyzed, the maximum power coefficient was obtained at k/c: 0.012. In addition, in the case where x/c: 0 - 0.50 location was applied to the roughness element, the power coefficient improved with increasing roughness height. Thus, it has been observed that the roughness element, which is a passive control technique, contributes to the aerodynamic performance of the turbine by reducing the flow separations in VAWTs.