Date of download: 10/25/2017 Copyright © ASME. All rights reserved. From: Turbine Inflow Characterization at the National Wind Technology Center J. Sol. Energy Eng. 2013;135(3):031017-031017-11. doi:10.1115/1.4024068 Figure Legend: The National Wind Technology Center. (a) A Siemens utility-scale turbine with 80-m hub height is in the foreground of the picture. The 135-m M4 tower is visible to the left. Photo by Dennis Schroeder, NREL/PIX 19015. (b) Relief map, courtesy of Joe Smith, NREL.

Date of download: 10/25/2017 Copyright © ASME. All rights reserved. From: Turbine Inflow Characterization at the National Wind Technology Center J. Sol. Energy Eng. 2013;135(3):031017-031017-11. doi:10.1115/1.4024068 Figure Legend: Schematic view of the NWTC 135-m M4 inflow monitoring tower. Boom heights are approximate. All booms face 285 deg.

Date of download: 10/25/2017 Copyright © ASME. All rights reserved. From: Turbine Inflow Characterization at the National Wind Technology Center J. Sol. Energy Eng. 2013;135(3):031017-031017-11. doi:10.1115/1.4024068 Figure Legend: Frequency and speed of valid measurements of winds at 80 m above ground, from 1/1/1996 to 12/2031/2010 on the M2 tower. Data are grouped by direction in 7.5 deg bins, and then colored to show wind speeds in 2 m s−1 bins. The distance from the origin shows the cumulative frequency of winds in that direction sector.

Date of download: 10/25/2017 Copyright © ASME. All rights reserved. From: Turbine Inflow Characterization at the National Wind Technology Center J. Sol. Energy Eng. 2013;135(3):031017-031017-11. doi:10.1115/1.4024068 Figure Legend: Comparison of wind speeds measured by LIDAR, sonic anemometers and cup anemometers on the M4 tower

Date of download: 10/25/2017 Copyright © ASME. All rights reserved. From: Turbine Inflow Characterization at the National Wind Technology Center J. Sol. Energy Eng. 2013;135(3):031017-031017-11. doi:10.1115/1.4024068 Figure Legend: Velocity and turbulence profiles for WNW flows (285 deg±15 deg) at 11≤U(76)≤13 m s−1 from 10/7/2011 to 11/7/2011. Data are grouped by stability (Table 2). Markers show mean values; bars show the interquartile range. Data are displaced less than 1 m vertically for visibility.

Date of download: 10/25/2017 Copyright © ASME. All rights reserved. From: Turbine Inflow Characterization at the National Wind Technology Center J. Sol. Energy Eng. 2013;135(3):031017-031017-11. doi:10.1115/1.4024068 Figure Legend: Variation of (a) mean TKE and (b) peak hub-height CTKE at 76 m above ground with |RiS|3 m s−1 and flows from the WNW sector (285±15 deg). Upper panels show all data. Lower panels show the statistics of data in each stability class (Table 2), where the divisions between classes are shown in the upper panels with dashed lines. Statistics include the 5th-95th percentile range (vertical line), 25th-75th percentile range (box) and median (horizontal line). Data points in the highest and lowest 5th percentiles are plotted individually.

Date of download: 10/25/2017 Copyright © ASME. All rights reserved. From: Turbine Inflow Characterization at the National Wind Technology Center J. Sol. Energy Eng. 2013;135(3):031017-031017-11. doi:10.1115/1.4024068 Figure Legend: Profiles of velocity and turbulence parameters for SSE flows (175 deg ± 15 deg) at 11≤U(76)≤13 m s−1. Plots use the same data and conventions as Fig. 5.

Date of download: 10/25/2017 Copyright © ASME. All rights reserved. From: Turbine Inflow Characterization at the National Wind Technology Center J. Sol. Energy Eng. 2013;135(3):031017-031017-11. doi:10.1115/1.4024068 Figure Legend: Diurnal cycles of RiS from 3 to 134 m, and z/L at 76 m. Stability classes are listed in Table 2. Data are 10-min average values from 10/7/2011 to 11/7/2011. Data include U(76)>3 m s−1 and exclude the tower wake (75 deg≤WD¯≤135 deg).

Date of download: 10/25/2017 Copyright © ASME. All rights reserved. From: Turbine Inflow Characterization at the National Wind Technology Center J. Sol. Energy Eng. 2013;135(3):031017-031017-11. doi:10.1115/1.4024068 Figure Legend: Comparison of the layer stability measures (a) Ri and RiS and (b) layer stability measure RiS with the normalized Monin–Obukhov length, z/L, at the hub height (76 m). The Businger–Dyer relationship (Eq. (21)) is shown for reference. Data include U(76)>3 m s−1 and exclude the tower wake (75 deg≤WD¯≤135 deg).