| Abstrakt: |
The effect of interaction between wake generated by wind turbines is particularly significant in offshore wind farms, because the turbulence in the ambient flow is low, thus, the wind turbine wake diffuses at the slower rate with the surrounding flow. As a result, efficiency of wind farms strongly depends on the turbine spacing inside the farm. The current study investigates the effect of wind turbine sitting on the flow fields and performance of offshore wind farms. To that end, large eddy simulations (LES) are performed for seven different wind farm layouts (three aligned and four staggered) with varying turbine spacing and number, while the farm area is same for all the cases. Better wake recovery is observed for the staggered layouts, and this can be attributed to the larger streamwise spacing for this layout. However, the spanwise averaged wind speeds are lower for the staggered layout indicating that more power is extracted by the wind farm from the flow. Spanwise-averaged turbulence kinetic energy increases downstream inside the aligned farm, while it remains roughly the same after the second turbine row. This is because the staggered layout is able to induce evenly distributed turbulence from the upstream region. In terms of power output, it is found that for the same wind farm area, power output of staggered wind farm can be as high as 30 to 40%. [ABSTRACT FROM AUTHOR] |
