Aerodynamic Performance Enhancement Using Active Flow Control on DU96-W-180 Wind Turbine Airfoil

Abstract

In this work, the objective was to investigate the influence of Active Flow Control on the improvement of a DU96-W-180 airfoil aerodynamic performance. A numerical simulation was done for incompressible unsteady low Reynolds Number flow at high angle of attack. The innovative approach was the use of an "Active Slat" where the periodic blowing effect was achieved by periodically opening and closing the slat passage. The major benefit of this concept is being flexible to a desired operating condition. A new OpenFOAM ® solver was developed from the existing pisoFoam solver to simulate the active slat flow control technique. To get the best aerodynamic performance, the active slat should operate at the domain dominant frequencies. A Fast Fourier Transform (FFT) was performed to achieve the optimum slat excitation frequency. These frequencies will help in controlling the inherent instabilities in the boundary layer and thus improving the aerodynamic performance. Finally, active flow control simulations were applied using different excitation. Using the optimum FFT excitation frequency ( 0.68 f = in the wake region) yields the best aerodynamic improvement of all tested frequencies. Improvements in lift coefficient were achieved up to 8%. Hence, the slatted airfoil is superior to the conventional clean configuration airfoil.

Wind Lens Performance Investigation at Low Wind Speed

“…A zone of dense mesh elements is created around the diffuser to capture the pressure gradient that occurs across it. Figure 4c shows inflation layers, which were also created around the diffuser walls to capture the boundary layer; a similar way was followed by Halawa et al 24) and Ibrahim et al 25) . The mesh elements everywhere else in the domain are unstructured 3D tetrahedral cells, created using Ansys meshing.…”

Experimental Investigation On The Spiral Pipe Performance For Particle-Laden Liquids

“…6 presents a comparison of the hydraulic gradient of the generalised Reynolds number on a circular pipe and spiral pipe. At low Re', the hydraulic gradient value decreased sharply until Re'=1x10 4 , especially for the circular pipes. Then, the growth occurred when the fluid flow enters the turbulent zone.…”

“…Two methods can be applied to obtain drag reduction, which directly relates to energy consumption reduction: active and passive control methods 4) . The active control method adds substances or additives through the working fluid 5,6) , while the passive control method tries to reduce drag by forming or reshaping a channel geometry or structure to obtain more effective flow 7,8) .…”

Analysis of the Use of Stern Foil on the High Speed Patrol Boat on Full Draft Condition

“…Velocity, coefficient of lift, and total lift force are directly affected by the profile of foil 17) . The NACA 4412 design, which was rated by the National Advisory Committee on Aeronautics (NACA), was chosen as a model in this experiment because it has a relatively high lift coefficient at zero-degree angle of attack [23][24][25] .…”