DOI: 10.5061/dryad.3tx95x6mp
title: Data from: Can IR images of the water surface be used to quantify the energy spectrum and the turbulent kinetic energy dissipation rate?

description: The bulk of the dataset is a direct numerical simulation (DNS) of an open
 channel flow with a shear-free surface. The DNS includes scalar, velocity,
 and divergence fields over 181 realizations. From the scalar field,
 another vector field was generated by a method called feature image
 velocimetry that successively cross-correlates the scalar fields to derive
 the underlying velocity field. The two velocity fields are then compared
 by their spectra, one from the DNS and the other derived from the scalar
 field.
description: The scripts included in the dataset are usable with matlab.
 Besides some of the plotting, it should be functional with
 octave.
description: # Can IR images of the water surface be used to quantify the energy
 spectrum and the turbulent kinetic energy dissipation rate? This dataset
 is of the top layer of a Direct Numerical Simulation (DNS) generated at
 Karlsruhe Institute of Technology, Karlsruhe Germany See - Pinelli et al.
 (2022) A second dataset was
 generated from the top DNS scaler field by cross-correlating the scaler
 fields in series. The method of cross-correlation is called Feature image
 velocimetry See - Metoyer et al. (2020)
 GRL_DataOCF12000\data
 Contains a few figures of the DNS surface layer, DNS coordinates
 "ocf12000_xyz" (used in scripts), and the Feature Image
 Velocimetry (FIV) dataset "imagedata_w60" imagedata_w60 - a .mat
 file that contains: -imagedata: a set of all 180 73x73 FIV velocity fields
 where imagedata{:,1} are the U (longitudinal) velocities fields
 imagedata{:,2} are the V (transverse) velocities fields Note - this set
 contains the filtered FIV velocities -imagedatainterpol: A set of all FIV
 velocities that interpolated -imagedataraw: The raw unfiltered FIV
 velocities -s: FIV settings table (window size and step size) -T: image
 vector containing each image number i.e.:
 "ocf12000_st_1500.tif", "ocf12000_st_1525.tif", ...,
 etc. G09_last60 - a .mat file that contains in the structure S: -Re:
 Reynolds number for flow -note: "G09 Flow statistics
 (non-dimensional) of last 60 time-units" -z: verticle diminention
 -zs: verticle distance from surface -urms: verticle profile of U_rms
 (longitudinal) -vrms: verticle profile of V_rms (horizontal) -wrms:
 verticle profile of W_rms (verticle) -eps: verticle profile of epsolon
 (the turbulent kinetic energy dissipation rate) GRL_DataOCF12000\images
 Contains normalized 8-bit ".tif" images of the DNS scalar field
 GRL_DataOCF12000\mat Contains the DNS dataset in ".mat" files.
 ocf12000_st_XXXX - DNS mat file containing velocity and scalar fields that
 are 1152x1552 each and co-located in space and time -c1: Scalar field with
 a Schmidt number of 7 -dwdz: Vertical divergence -parameter: DNS
 parameters \- Reynolds number of 12000 and schmidt number 7 -t: time stamp
 -u: longitudinal velocity field -v: transverse velocity field
 GRL_DataOCF12000\scripts Contains useful scripts to view and explore the
 dataset EK_spectra.m - matlab function that generates spectra for use in
 spectra_viewer.m isotropy_epsilon.m - opens and views the vertical profile
 of isotropy and epsilon plot_G09_last60.m - time-space averaged vertical
 profile of epsilon readsnaptop_ocf.m - Read DNS snapshot from
 GRL_DataOCF12000\mat spectra_viewer.m - calculate and view the spectra
 from the DNS and FIV measurements