Schematic of experimental setup.
Strakes to generate mean shear at the inflow.
Wind turbine model dimensions.
Wind turbine array and PIV measurement plane locations (top view). The turbine diameter is .
Photograph from the downstream area of the wind tunnel experiment, looking toward upstream direction.
Measured mean velocity profile of the inflow. The left figure (a) is in linear units, while the right figure (b) shows the data in lin-log units together with a log-law fit (solid line). The rough wall boundary layer profile is consistent with a roughness length (or equivalently, using Eq. (9) (with and ), to a velocity defect of ).
Reynolds stresses of the inflow measured using hot wires.
Longitudinal energy spectra of streamwise and cross-stream velocity components at measured by an X-wire probe: (solid line); (dashed line). The vertical arrow corresponds to the wavenumber of the PIV resolution .
Mean velocity contour plots obtained on the 18 PIV planes across the volume surrounding the target wind turbine. (a) is the streamwise velocity , (b) is the vertical mean velocity , and (c) is the transverse velocity .
Contour plots of variances (normal Reynolds stresses) obtained on the 18 PIV planes across the volume surrounding the target wind turbine. (a) Variance of streamwise velocity ; (b) variance of vertical velocity . (c) Contour plots of Reynolds shear stress .
Pressure distribution along the test section, measured through pressure tabs on the wind tunnel sidewalls at midheight of the test section using Dwyer electronic-point micromanometer. The gray dashed line denotes a mean pressure drop of across the wind turbine array. The distance is measured from the active grid.
Sketch explaining periodic data replication across the wind-turbine array used to estimate total horizontal average profiles from the available PIV data.
Vertical profile of horizontally averaged streamwise velocity using different averaging domains: Dash line: front region ; dot-dashed line: back region ; solid line: total domain, using periodic replication ; dotted line: total domain, using constant extrapolation . The horizontal dotted lines indicate the extent of the wind-turbine models, at and .
Vertical profile of horizontally averaged Reynolds shear stress, using different averaging domains: Dash line: front region ; dot-dashed line: back region ; solid line: total domain, using periodic replication .
Vertical profile of horizontally averaged Reynolds normal stresses (variances) using integration over the total domain using periodic replication. Solid line: streamwise variance , dashed line: wall-normal variance .
Vertical profile of horizontally averaged streamwise velocity using different averaging domains: Lines same as in Fig. 13. The gray dashed line below the wind turbines denotes a possible logarithmic profile using the measured friction velocity and a displacement velocity of . The gray dashed line above and below the wind turbines denotes possible logarithmic profiles using the measured friction velocities (see text).
Vertical profile of dispersive shear stress, computed from the spatial fluctuations in mean velocity (differences between the temporally averaged mean velocity and their horizontal average) using different averaging domains (lines as in Fig. 14).
Vertical profiles of , the turbulent kinetic energy dissipation in the horizontally averaged energy budget, for different averaging domains (lines: same as in Fig. 14).
Vertical profiles of , the kinetic energy dissipation in the horizontally averaged energy budget due to the dispersive stresses (lines: same as in Fig. 14).
Vertical profiles of of flux of kinetic energy due to turbulence transport, , for different averaging domains (lines: same as in Fig. 14).
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