Wind turbine shrouds are used to increase flow velocity entering the rotor and accordingly, the air mass flow rate through the turbine. In this study, the flow through a wind turbine shroud was investigated using experimental measurements and numerical computations. In the experimental study, four shroud arrangements were installed with inlet nozzle, diffuser and exit lens. The flow velocity profile was measured at the throat to evaluate the augmentation in flow velocity. The measurements were performed using a calibrated five-hole pressure probe. In the numerical procedure, the flow governing equations were solved. The two-dimensional Reynolds-Averaged Navier Stokes equations were solved with the standard k-ε turbulence model. The measurements were used to justify the validity of the numerical results. The results obtained through this study showed that the flow velocity at the throat was significantly increased above the incoming free stream velocity. This was attributed to the large recirculation zone behind the shroud with a low-pressure which draws more wind. The numerical calculations were used also to determine the location of the maximum velocity where the rotor would be installed. The velocity distribution at this location can be used to design the rotor and associated blade twist. The increase in the generated power was estimated using a simple method based on the throat velocity. |
