Segmented Ultralight Morphing Rotor, Demonstrator (SUMR-D)


The Segmented Ultralight Morphing Rotor (SUMR) Project ( is a revolutionary horizontal axis wind turbine design concept under Advanced Research Projects Agency–Energy (ARPA-E) sponsorship. The SUMR concept takes advantage of highly flexible blades that deflect significantly under load, and thus enable shedding of destructive forces to survive extreme wind events. While the overall SUMR project includes design and analysis of very large rotor blades, this dataset covers field experiments of the SUMR-D rotor, where ‘D’ stands for demonstrator. The SUMR-D rotor blades are gravo-aero-elastically scaled-down versions (approximately 21 m in length) of much larger blades (106.8 m long), which were designed for a 13 MW, IEC Class IIA (IEC 61400-1) wind turbine (SUMR-13). The SUMR-D blade design was created to validate, through a field measurement campaign, the predicted load response, control system characteristics, and performance of the larger SUMR-13. At about 1:4 scale of the SUMR-13, the SUMR-D rotor blade is ~21 m long and weighs ~575 kg, and was designed to mount on the CART2, a 600 kW research wind turbine installed at the NREL Flatirons Campus near Boulder, CO. The SUMR-D rotor operated only in very light winds (5-12 m/s) with a rated rotor power of about 50 kW.

The DAP ARPA-E SUMR database contains the measurements acquired via field experiments using the SUMR-D rotor installed on the CART2 wind turbine at the NREL Flatirons Campus. The goals of the field experiments were to: 1 collect blade loading response from operational and parked conditions and 2) gather blade deflection data via video camera footage.


The Controls Advanced Research Turbine 2-bladed (CART2) is a 600kW research turbine located at the NREL Flatirons Campus, south of Boulder, CO. It has a hub height of 120 ft (36.6m) and is equipped with a dedicated meteorological mast located approximately two rotor diameters upstream from the predominant wind direction. For the ARPA-E SUMR project, the CART2 was outfitted with two highly flexible blades specifically designed and built for the project. The turbine was also operated in a downwind configuration, but with the rotor spinning counterclockwise from an observer standing upwind of the turbine. The blades were designed to represent a gravo-aero-elastically scaled-down version of a 13 MW, IEC Class IIA (IEC 61400-1) wind turbine (SUMR-13). The blades were installed on a blade root adapter plate such that a high coning angle could be achieved for the rotor. The pitch actuation remained on the rotor, hence the coning angle varied with pitch angle. At full feather pitch (90°), the coning angle was 0°, and at run pitch (0°), the coning angle was 15°.

The ~21m blades were outfitted with strain gauges at the blade root and 13m from the root in both flap and edge using full bridges. The strain gauges were calibrated using gravity and the known blade mass to convert the strain voltage into the recorded bending moment. Additionally, visual targets were placed on the trailing edge of the blade and a video camera was installed at the blade root for each blade. Photogrammetry measurements were taken to allow video postprocessing to be done to convert the video footage into blade deflection data.

With this setup, the turbine proceeded to collect field experimentation data at the NREL Flatirons Campus. Data was collected while the turbine was operational, parked with the rotor both locked and free, as well as transients including turbine startup, shutdown, and emergency stop.


The data format for these files is very similar to the data format for the UAE6 data on the DAP. The data is written in binary format, and scripts will need to be used to load the data and extract relevant information. MATLAB scripts are included below which load in the CART data and header information. If desired, a user can read through these scripts and copy the loading procedure into his/her own programming environment.

Additionally, database files have been generated for this data set to aid in locating specific data records of interest. The database files are available in a Microsoft Excel spreadsheet format as well as a MATLAB matrix format. The database files contain a timestamp in MATLAB datenum format which is the beginning time of the record, the filename with which the data record can be found, flags which identify the state of the turbine, and the statistics of each data channel for that data record. The statistics for each channel include the mean, standard deviation, maximum value, and minimum value. The flags are as follows:

  1. isOperate – this flag is 1 if the turbine was operating nominally for the duration of the data record; it is 0 otherwise, including if the turbine was in a transient state for starting up or shutting down for a portion of the data record
  2. isIdle – this flag is 1 if the turbine was not operating, not starting up, and not shutting down; it is 0 otherwise.
  3. isParked – this flag is 1 if the turbine brakes are applied to the drivetrain for the entire duration of the data record; it is zero otherwise.
  4. isPitchRun – this flag is 1 if both of the turbine blades are at the run pitch angle for the duration of the data record; it is zero otherwise.
  5. isPitchFeather – this flag is 1 if both f the turbine blades are at the feather pitch angle for the duration of the data record; it is zero otherwise.
  6. isRotorHorizontal – this flag is 1 if the turbine rotor is horizontal for the duration of the data record; it is zero otherwise.
  7. isRotorVertical – this flag is 1 if the turbine rotor is vertical for the duration of the data record; it is zero otherwise.

Insert potential description of video data here.

Support Files

MATLAB Scripts
• cartLoadHdrU.m - This script loads in the header file information for the data file (the header is embedded in each data file at the beginning)
• cartPlotU.m - This is a GUI that allows you to interactively look at different channels. To use it, run the script in Matlab, and load in the data file(s) of interest. From there, you can select different channels, and plot things against each other. Note that this script have issues with later versions of MATLAB. The preferred version to use is R2011b.
• loadcartU.m - This script loads in a CART data file and puts it in your workspace as a Matlab matrix. You can call this script from your own Matlab scripts to do your own analysis.
• charts.mat - This is a dependency file needed for the other scripts. It allows you to make custom pre-selections for cartPlotU.m

Excel Database Files
• sumr_d_10-Min_Raw_Database – this database contains records of 10-minute averaged data points.
• sumr_d_5-Min_Raw_Database – this database contains records of 5-minute averaged data points (this is the default length of data for a CART data file).
• sumr_d_CycleAvg_Raw_Database – this database contains records of data that has been averaged over one revolution of the rotor. This only contains data for when the turbine was operational and does not have the flags mentioned earlier.

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