Development and interaction of rotor wakes

Experiments on line arrays of horizontal-axis hydroturbines

“…For each measuring window, the average velocity field was obtained by phase averaging of 200 realizations. The measuring error of PIV was 3-5% [29].…”

“…Next, it was found in Ref. [29], that disks can be used to replace rotors when testing line-array models, but they should not be located immediately upstream of the rotor being investigated. Hence, testing the third rotor in an array, for example, could use an upstream disk-rotor configuration, whereas a disk-disk or rotor-disk configuration could not be used [28].…”

“…Our configurations were guided by previous studies that showed that the velocity deficit and flow oscillations in the wake behind the disk-rotor system is identical to the rotor-rotor system [29]. Elements were located at equal distances, L x = 3D, 4D, 5D, 6D, 7D, corresponding to a typical range of locations of wind turbines in a wind farm.…”