Input files for LBM-DEM simulation of immersed granular collapse

The input files for the case D-VB. The files with the name started with "in" are input files for LIGGGHTS (https://github.com/CFDEMproject/LIGGGHTS-PUBLIC) and the C++ file is the input file for Palabos (http://www.palabos.org/). The input files are called in the following sequence:1. in.cloud - generate the particles2. in.rain - create a granular column by turning on the gravity3. in.trim - trim the particles so that the aspect ratio is 0.84. damBreakImmersed.cpp - solve fluid filed using LBM5. in.immerse - immersed the granular column6. in.cycle - called by "damBreakImmersed.cpp" to advance the DEM simulationOther cases with different column sizes and packing densities can be simulated by the same input files with adjustments on the geometry and friction coefficients during sample preparation.