This readme.txt file was generated on 20220517 by Jorge E. San Juan Recommended citation for the data: San Juan, Jorge E; Wei, William G; Yang, Judy Q. (2022). Flow and clay erosion data taken and processed at SAFL in a grid-turbulence tank Fall 2021-Spring 2022. Retrieved from the Data Repository for the University of Minnesota, https://doi.org/10.13020/vxrv-7e20. ------------------- GENERAL INFORMATION ------------------- 1. Title of Dataset: Flow and clay erosion data taken and processed at SAFL in a grid-turbulence tank Fall 2021-Spring 2022 2. Author Information Principal Investigator Contact Information Name: Judy Q. Yang Institution: University of Minnesota Twin Cities Address: St. Anthony Falls Laboratory Room 376 2 3rd Ave SE Minneapolis, MN 55414 Email: judyyang@umn.edu ORCID: 0000-0001-6272-1266 Associate or Co-investigator Contact Information Name: Jorge E. San Juan Institution: University of Minnesota Twin Cities Address: St. Anthony Falls Laboratory Room 390 2 3rd Ave SE Minneapolis, MN 55414 Email: jsanjuan@umn.edu ORCID: 0000-0003-0848-150X Associate or Co-investigator Contact Information Name: William G. Wei Institution: University of Minnesota Twin Cities Address: St. Anthony Falls Laboratory Room 364 2 3rd Ave SE Minneapolis, MN 55414 Email: wei00235@umn.edu ORCID: 0000-0001-5511-9242 3. Date published or finalized for release: To be determined. 4. Date of data collection: 20211104-20220120 5. Geographic location of data collection: Minneapolis, Minnesota, USA 6. Information about funding sources that supported the collection of the data: University of Minnesota Twin Cities 7. Overview of the data: Here we present a dataset containing raw imaging and processed data of clay erosion and near-bed turbulence. This dataset supports our study of the impact of salinity and consolidation on the microstructure and erosion threshold of cohesive sediments. The flow and erosion measurements were taken inside a grid-turbulence tank at the St. Anthony Falls Laboratory at the University of Minnesota Twin Cities. We set up the water salinity at a prescribed concentration in part-per-thousands and two clay consolidation conditions (unconsolidated and consolidated after 17 hours) for each experimental case. Here we incorporate detailed near-bed turbulence measurements to quantify the erosive effect of the turbulent water flow. We also include laponite (smectite clay)'s surface erosion from laser-induced fluorescence and image processing. The raw data consists of fluorescence-labeled clay's surface and raw confocal microscopy imaging of the clay dispersions (clay microstructures). The processed data includes: (i) spatial-averaged turbulent kinetic energy, (ii) Reynolds stresses, (iii) time series of image structural-similarity index for clay erosion. We release this dataset to make it available for understanding, evaluating, and building upon our reported research. -------------------------- SHARING/ACCESS INFORMATION -------------------------- 1. Licenses/restrictions placed on the data: CC0 1.0 Universal 2. Links to publications that cite or use the data: To be determined. 3. Was data derived from another source? No, it was not. 4. Terms of Use: Data Repository for the U of Minnesota (DRUM) By using these files, users agree to the Terms of Use. https://conservancy.umn.edu/pages/drum/policies/#terms-of-use --------------------- DATA & FILE OVERVIEW --------------------- 1. File List A. Filename: confocal_microscopy.zip Short description: Compressed zip file containing four confocal images of clay dispersions. Confocal images' extension is .nd2 and can be open through NIS Elements Viewer, Laboratory Imaging (https://www.microscope.healthcare.nikon.com/products/software/nis-elements/viewer). Each confocal image is accompanied with its exported TIFF image. Consolidated cases are indicated with the prefix "cons" while unconsolidated cases are indicated with prefix "uncons". Salinity condition of the sample is labeled in ionic strength concentration [M] as in "0pXXXXM", where the letter "p" indicates the period mark. Clay concentration was 5%w/w for all samples. B. Filename: cons_0p010M_rep04.zip Short description: Compressed zip file containing the captures images of the consolidated clay bed's surface at a clay concentration of 5%w/w and water salinity 0.77 ppt (ionic strength of 0.01 M). Images are organized in folders corresponding 5-minutes of capturing time at a prescribed motor-grid oscillation frequency. Folders are labeled after the motor frequency reading. The accompanying CSV file key_rpm_vs_kt.csv indicates the corresponding spatial-averaged turbulent kinetic energy level of each motor frequency reading. All images were taken at a 1Hz rate. C. Filename: uncons_0p010M_rep03.zip Short description: Compressed zip file containing the captures images of the unconsolidated clay bed's surface at a clay concentration of 5%w/w and water salinity 0.77 ppt (ionic strength of 0.01 M). Images are organized in folders corresponding 5-minutes of capturing time at a prescribed motor-grid oscillation frequency. Folders are labeled after the motor frequency reading. The accompanying CSV file key_rpm_vs_kt.csv indicates the corresponding spatial-averaged turbulent kinetic energy level of each motor frequency reading. All images were taken at a 1Hz rate. D. Filename: mean_structural_similarity.zip Short description: Compressed zip file containing series of mean structural similarity index (ssim) as a function of turbulent kinetic energy (kt). Each text file within the folder corresponds to a consolidation case (labeled "cons" or "uncons" for consolidated or unconsolidated clay, respectively) and salinity condition (labeled in ionic strength concentration [M] as in "0pXXXXM", where "p" replace the period mark). Also, each text file contains series mean structural similarity index from each replica measured (labeled as ssimXX). E. Filename: rpm-vs-kt.txt Short description: Text file containing the series of spatial-averaged turbulent kinetic energy (kt) produced near the bed of the turbulence tank as a function of its grid oscillation frequency (grid freq.). F. Filename: rpm-vs-uw.txt Short description: Text file containing the series of spatial-averaged Reynolds stress u'w' (u'w') produced near the bed of the turbulence tank as a function of its grid oscillation frequency (grid freq.). G. Filename: salinity-vs-kcrit_cons.txt Short description: Text file containing the series of critical turbulent kinetic energy (kcrit) for consolidated clay erosion as a function of water salinity in part-per-thousands (ppt). H. Filename: salinity-vs-kcrit_uncons.txt Short description: Text file containing the series of critical turbulent kinetic energy (kcrit) for unconsolidated clay erosion as a function of water salinity in part-per-thousands (ppt). I. Filename: salinity-vs-taucrit_cons.txt Short description: Text file containing the series of critical bed shear stress (taucrit) for consolidated clay erosion as a function of water salinity in part-per-thousands (ppt). J. Filename: salinity-vs-taucrit_uncons.txt Short description: Text file containing the series of critical bed shear stress (taucrit) for unconsolidated clay erosion as a function of water salinity in part-per-thousands (ppt). K. Filename: 2d_turbulent_kinetic_energy.zip Short description: Compressed zip file containing the 2-dimensional turbulent kinetic energy field near the bed inside a grid-turbulence tank organized in columns by longitudinal (x) and vertical (z) coordinates. Turbulent kinetic energy fields are organized in text files corresponding to prescribed motor-grid oscillation frequencies. The text files are labeled after the motor frequency reading. The accompanying CSV file key_rpm_vs_kt.csv indicates the corresponding spatial-averaged turbulent kinetic energy level of each motor frequency reading. L. Filename: 2d_Reynolds_stress_uw.zip Short description: Compressed zip file containing the 2-dimensional Reynolds stress field u'w' near the bed inside a grid-turbulence tank organized in columns by longitudinal (x) and vertical (z) coordinates. The Reynolds stress fields are organized in text files corresponding to prescribed motor-grid oscillation frequencies. The text files are labeled after the motor frequency reading. The accompanying CSV file key_rpm_vs_kt.csv indicates the corresponding spatial-averaged turbulent kinetic energy level of each motor frequency reading. M. Filename: luminance_diff_cons_0p005M_rep03.txt Short description: Text file containing the 2-dimensional field of luminance difference between consolidated clay's surface initial condition and the its final eroded condition at ionic strength 0.005 M. Luminance difference is organized in columns by longitudinal (x) and vertical (z) coordinates. N. Filename: luminance_diff_cons_0p030M_rep02.txt Short description: Text file containing the 2-dimensional field of luminance difference between consolidated clay's surface initial condition and the its final eroded condition at ionic strength 0.030 M. Luminance difference is organized in columns by longitudinal (x) and vertical (z) coordinates. 2. Relationship between files: The files presented here show the water flow and clay erosion measurements, where the moving water drove the erosion of the clay samples. -------------------------- METHODOLOGICAL INFORMATION -------------------------- 1. Description of methods used for collection/generation of data: Flow velocity measurements were collected using a Particle Image Velocimetry (PIV) system. This is an optical technique that capture instantaneous images of a particle-seeded flow to generate 2-dimensional velocity fields. Clay erosion measurements were collected using a laser-induced fluorescence technique. Using the same PIV system, we fluorescently labeled the clay samples and capture images of the clay surface through increasingly energetic flow conditions inside the turbulence tank. 2. Methods for processing the data: Processed flow data was generated through the Matlab application PIVLab. Clay images were processed through python and Matlab to obtain series of mean structural-similarity indices. 3. Instrument- or software-specific information needed to interpret the data: None. 4. Standards and calibration information, if appropriate: None. 5. Environmental/experimental conditions: We tested 10 erosion conditions: 5 water salinity concentrations (0.15, 0.26, 0.77, 1.52, and 3.04 ppt) and 2 consolidation conditions (unconsolidated and 17-hour consolidation). Each erosion test consisted on 16 increments of flow energy conditions with turbulent kinetic energy from 0 to 13 cm2/s2. 6. Describe any quality-assurance procedures performed on the data: Each experimental condition (combination of water salinity and clay consolidation) was replicated 4 times to quantify the standard error. 7. People involved with sample collection, processing, analysis and/or submission: Jorge E. San Juan, William G. Wei, and Judy Q. Yang. ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: confocal_microscopy.zip ----------------------------------------- 1. Number of variables: 2 2. Number of cases/rows: 2 3. Missing data codes: N/A 4. Variable List A. Name: salinity Description: Salinity water measured in ionic strength in moles [M]. Label in filename: "0pXXXXM" (letter "p" indicates the period mark) B. Name: consolidation Description: Clay consolidation. Label in filename: "cons" (consolidated) and "uncons" (unconsolidated) ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: cons_0p010M_rep04.zip ----------------------------------------- 1. Number of variables: 1 2. Number of cases/rows: 16 3. Missing data codes: N/A 4. Variable List A. Name: turbulence tank's grid oscillation frequency Description: Frequency reading in the motor driving the oscillating grid. Label in filename: "motor_XXpX" (letter "p" indicates the period mark) ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: uncons_0p010M_rep03.zip ----------------------------------------- 1. Number of variables: 1 2. Number of cases/rows: 16 3. Missing data codes: N/A 4. Variable List A. Name: turbulence tank's grid oscillation frequency Description: Frequency reading in the motor driving the oscillating grid. Label in filename: "motor_XXpX" (letter "p" indicates the period mark) ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: mean_structural_similarity.zip ----------------------------------------- 1. Number of variables: 2 2. Number of cases/rows: 10 3. Missing data codes: N/A 4. Variable List A. Name: mean structural-similarity index Description: Measurement of image similarity between the undisturbed clay sample and the eroding clay sample. Label in text file: "ssimXX [1]" B. Name: turbulent kinetic energy Description: Spatial-averaged turbulent kinetic energy measured near the bed of a grid-turbulence tank. Label in text file: "kt [cm2/s2]" C. Name: salinity Description: Salinity water measured in ionic strength in moles [M]. Label in filename: "0pXXXXM" (letter "p" indicates the period mark) D. Name: consolidation Description: Clay consolidation. Label in filename: "cons" (consolidated) and "uncons" (unconsolidated) ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: rpm-vs-kt.txt ----------------------------------------- 1. Number of variables: 2 2. Number of cases/rows: 14 3. Missing data codes: N/A 4. Variable List A. Name: grid oscillation frequency Description: Frequency of oscillating grid inside the turbulence tank in rpm. Label in text file: "grid freq. [rpm]" B. Name: turbulent kinetic energy Description: Spatial-averaged turbulent kinetic energy measured near the bed of a grid-turbulence tank. Label in text file: "kt [cm2/s2]" ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: rpm-vs-uw.txt ----------------------------------------- 1. Number of variables: 2 2. Number of cases/rows: 14 3. Missing data codes: N/A 4. Variable List A. Name: grid oscillation frequency Description: Frequency of oscillating grid inside the turbulence tank in rpm. Label in text file: "grid freq. [rpm]" B. Name: Reynolds stress u'w' Description: Spatial-averaged Reynolds stress u'w' measured near the bed of a grid-turbulence tank. Label in text file: "u'w' [cm2/s2]" ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: salinity-vs-kcrit_cons.txt ----------------------------------------- 1. Number of variables: 2 2. Number of cases/rows: 5 3. Missing data codes: N/A 4. Variable List A. Name: salinity Description: Water salinity in parts-per-thousands. Label in text file: "salinity [ppt]" B. Name: Critical turbulent kinetic energy Description: Critical spatially-averaged turbulent kinetic energy for clay erosion measured near the bed of a grid-turbulence tank. Label in text file: "kcrit [cm2/s2]" C. Name: Standard error Description: Standard error of the critical turbulent kinetic energy for clay erosion. Label in text file: "std error [cm2/s2]" ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: salinity-vs-kcrit_uncons.txt ----------------------------------------- 1. Number of variables: 2 2. Number of cases/rows: 5 3. Missing data codes: N/A 4. Variable List A. Name: salinity Description: Water salinity in parts-per-thousands. Label in text file: "salinity [ppt]" B. Name: Critical turbulent kinetic energy Description: Critical spatially-averaged turbulent kinetic energy for clay erosion measured near the bed of a grid-turbulence tank. Label in text file: "kcrit [cm2/s2]" C. Name: Standard error Description: Standard error of the critical turbulent kinetic energy for clay erosion. Label in text file: "std error [cm2/s2]" ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: salinity-vs-taucrit_cons.txt ----------------------------------------- 1. Number of variables: 2 2. Number of cases/rows: 5 3. Missing data codes: N/A 4. Variable List A. Name: salinity Description: Water salinity in parts-per-thousands. Label in text file: "salinity [ppt]" B. Name: Critical bed shear stress Description: Critical spatially-averaged bed shear stress for clay erosion measured near the bed of a grid-turbulence tank. Label in text file: "taucrit [N/m2]" C. Name: Standard error Description: Standard error of the critical bed shear stress for clay erosion. Label in text file: "std error [cm2/s2]" ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: salinity-vs-taucrit_uncons.txt ----------------------------------------- 1. Number of variables: 2 2. Number of cases/rows: 5 3. Missing data codes: N/A 4. Variable List A. Name: salinity Description: Water salinity in parts-per-thousands. Label in text file: "salinity [ppt]" B. Name: Critical bed shear stress Description: Critical spatially-averaged bed shear stress for clay erosion measured near the bed of a grid-turbulence tank. Label in text file: "taucrit [N/m2]" C. Name: Standard error Description: Standard error of the critical bed shear stress for clay erosion. Label in text file: "std error [N/m2]" ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: 2d_turbulent_kinetic_energy.zip ----------------------------------------- 1. Number of variables: 1 2. Number of cases/rows: 15 3. Missing data codes: N/A 4. Variable List A. Name: turbulent kinetic energy Description: Turbulent kinetic energy near the bed inside a grid-turbulence tank. Label in text file: "kt [cm2/s2]" ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: 2d_Reynolds_stress_uw.zip ----------------------------------------- 1. Number of variables: 1 2. Number of cases/rows: 15 3. Missing data codes: N/A 4. Variable List A. Name: turbulent kinetic energy Description: Reynolds stress u'w' near the bed inside a grid-turbulence tank. Label in text file: "u'w' [cm2/s2]" ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: luminance_diff_cons_0p005M_rep03.txt ----------------------------------------- 1. Number of variables: 1 2. Number of cases/rows: 1 3. Missing data codes: N/A 4. Variable List A. Name: luminance difference Description: Luminance difference between consolidated clay's surface initial condition and the its final eroded condition. Label in text file: "di [1]" ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: luminance_diff_cons_0p030M_rep02.txt ----------------------------------------- 1. Number of variables: 1 2. Number of cases/rows: 1 3. Missing data codes: N/A 4. Variable List A. Name: luminance difference Description: Luminance difference between consolidated clay's surface initial condition and the its final eroded condition. Label in text file: "di [1]"