Lab-scale measurements of wind farm blockage effects

Abstract

The inflow an individual wind turbine experiences in a farm layout is strongly dependent on flow interaction effects with the turbines surrounding it. In addition to the well-known wake flows, lateral and upstream flow interaction effects, commonly described as wind farm blockage effects, have also recently gained some attention. In this work, flow measurements in the upstream induction zone of neighboring turbines are presented for different arrangements of three to seven porous actuator discs. It is shown how the upstream induction zones of individual discs merge into a single zone when decreasing the lateral spacing between three discs. As a result, the central disc experiences a higher thrust force than its neighboring discs. For farm arrangements in two rows, an aligned disc setup is observed to result in a larger upstream velocity decrease than offset arrangements.