This readme.txt file was generated on 20200122 by Shanda Hunt, DRUM curator Edited on 20200203 by Michael Heisel ------------------- GENERAL INFORMATION ------------------- 1. Title of Dataset Particle image velocimetry measurements of smooth- and rough-wall turbulence from the SAFL Atmospheric Boundary Layer wind tunnel 2. Author Information Principal Investigator Contact Information Name: Michele Guala, Associate Professor of Civil, Environmental, and Geo-Engineering Institution: University of Minnesota Address: St. Anthony Falls Laboratory Email: mguala@umn.edu Website: http://personal.cege.umn.edu/~guala/ ORCID: 0000-0002-9788-8119 Associate or Co-investigator Contact Information Name: Michael Heisel Institution: University of Minnesota Address: St. Anthony Falls Laboratory (PhD candidate in Civil Engineering) Email: heise070@umn.edu ORCID: 0000-0002-4200-5550 3. Date of data collection 20180901 to 20181220 4. Geographic location of data collection Atmospheric Boundary Layer Wind Tunnel at St. Anthony Falls Laboratory (SAFL), University of Minnesota 5. Information about funding sources that supported the collection of the data: Institute on the Environment (IonE); National Science Foundation CAREER grant (NSF-CBET-1351303) -------------------------- SHARING/ACCESS INFORMATION -------------------------- 1. Licenses/restrictions placed on the data: CC0 1.0 Universal https://creativecommons.org/publicdomain/zero/1.0/ 2. Links to publications that cite or use the data: Heisel M, de Silva CM, Hutchins N, Marusic I, and M Guala (2020). On the mixing length eddies and logarithmic mean velocity profile in wall turbulence. Journal of Fluid Mechanics, 887, R1. doi.org/10.1017/jfm.2020.23. 6. Recommended citation for the data: Heisel, Michael; Guala, Michele. (2020). Particle image velocimetry measurements of smooth- and rough-wall turbulence from the SAFL Atmospheric Boundary Layer wind tunnel. Retrieved from the Data Repository for the University of Minnesota, http://hdl.handle.net/11299/211303. --------------------- DATA & FILE OVERVIEW --------------------- 1. File List file_description.pdf Description of data files, variables, and flow parameters 227.3Kb PDF smooth_07ms_velocity_vectors.mat PIV vector fields 1.508Gb application/matlab smooth_07ms_scaling_parameters.mat Flow parameters 387bytes application/matlab smooth_10ms_velocity_vectors.mat PIV vector fields 1.505Gb application/matlab smooth_10ms_scaling_parameters.mat Flow parameters 387bytes application/matlab mesh_07ms_velocity_vectors_A.mat PIV vector fields 751.0Mb application/matlab mesh_07ms_velocity_vectors_B.mat PIV vector fields 745.7Mb application/matlab mesh_07ms_scaling_parameters.mat Flow parameters 438bytes application/matlab mesh_10ms_velocity_vectors_A.mat PIV vector fields 774.1Mb application/matlab mesh_10ms_velocity_vectors_B.mat PIV vector fields 774.2Mb application/matlab mesh_10ms_scaling_parameters.mat Flow parameters 438bytes application/matlab 2. Relationship between files: The data are provided in the MATLAB data file format (.mat), with a separate set of files for each flow case. The files are named based on the surface (i.e. smooth or mesh) and free-stream velocity (i.e. 7 m/s or 10 m/s) for the given case. The smooth-wall velocity vector files each contain vectors for 10,000 PIV frames. The rough-wall velocity vector data are separated into two files – each with 5,000 PIV frames – based on the position of the laser within the roughness pattern. Flow parameters for each case are included in a separate .mat file from the vectors. 3. Instructions for running files The larger "vector" files are MATLAB 7.3 files (meaning they should be handled/viewed like HDF5 files) The regular MATLAB GUI can't handle files of this size, it can read in the variables but will not display the actual values ["Cannot display summaries of variables with more than 524288 elements"]. Use Python module (https://github.com/skjerns/mat7.3) Here's a stackoverlflow article with other options as well: https://stackoverflow.com/questions/874461/read-mat-files-in-python -------------------------- METHODOLOGICAL INFORMATION -------------------------- 1. Description of methods used for collection/generation of data: The particle image velocimetry (PIV) system included a Big Sky 532 nm Nd:YAG double-pulsed laser, a TSI Powerview 4 MP camera, and TSI Insight 4G synchronizer and acquisition software. The raw images were processed using in-house cross-correlation code with two passes and 50% vector overlap. The measurements are not time-resolved. 2. Environmental/experimental conditions: Woven wire mesh was used for the rough-wall cases. The mesh had 3 mm diameter and 25 mm opening size, i.e. distance between wires. The mesh height above the wind tunnel floor varied from 3 mm to 6 mm based on the overlapping, woven wires. The wire mesh covered the test section and the 16 m between the wind tunnel contraction and test section. See the File_Description document for a photo of the woven wire mesh and an overview of the flow parameters for each case. 3. Describe any quality-assurance procedures performed on the data: The in-house cross-correlation code performed universal outlier detection following Westerweel & Scarano (Exp. Fluids 2005). The scheme detected and replaced outlier vectors using linear interpolation. --------------------------- DATA-SPECIFIC INFORMATION --------------------------- See file_description.pdf