Two-dimensional images of unstable infiltration in initially dry heterogeneous porous media in laboratory experiments

Abstract

We provide a data set of unstable infiltration into initially dry homogeneous and heterogeneous porous media. The data set contains small 2D experiments (Exp. 3-11 in Table 12 of the associated manuscript) as well as selected experiments conducted in large tanks. For small 2D experiments, radiographic images are provided, while large 2D experiments are documented via RGB images. Datasets contain a reference image 0.* before the onset of finger formation, where the porous media in the domain, except for the upper fine layer, is completely dry. For the radiography dataset, the measured neutron intensity corresponds to I in Eq. [1-2] and the reference image “0.fits” corresponds to Idry in Eq. [2] of the manuscript. Datasets for radiography (Exp. 3-11) contain an additional empty empty.fits image where the flow cell is absent. Other filenames relate to time in seconds after onset of finger formation The radiography dataset (Exp. 3-11) is saved in the Flexible Image Transport System (FITS) format, which can be opened with common image processing tools such as ImageJ or computing environments such as Matlab. More information regarding the file format can be found at https://fits.gsfc.nasa.gov/fits_home.html. Each FITS file contains a 512 by 512 matrix of pixelwise measured neutron intensities [neutrons/(px*s)]. The dimensions of the pixels can be found in the table below. Fits files furthermore contain supporting information that has not been utilized in the manuscript but might prove useful, such as number of bits per data pixel and exposure time. For evaluation as conducted in the manuscript, the radiography raw data given in this dataset has been processed to eliminate the background noise with a wiener noise-removal filter. More Information on the radiography facility can be found at https://www.psi.ch/sinq/PublicationPolicyEN/NEUTRA.pdf.