LES-DEM computations of barchan dunes

Published: 10 August 2022| Version 1 | DOI: 10.17632/zhnngnvvz8.1
Contributors:
Nicolao Lima,
Willian Righi Assis,
carlos alvarez,
Erick Franklin

Description

These files contain the 20 first seconds of results of a CFD-DEM simulation of a barchan dune formation and the codes used to analyze those results. The simulation was carried out using the open-source free CFDEM software, which couples the open-source CFD code OpenFOAM with the open-source DEM code LIGGGHTS. The simulations were tested and the results agreed quite well with the expected results from the literature. The dataset contains the results of an example case, from both the DEM and the CFD sides, and we also share the full Octave code for post-processing those results.

Files

Steps to reproduce

The Simulation folder contains the first 20 seconds of results for the particles (DEM folder) and for the fluid (CFD folder). The former can be viewed by the Ovito software, while the latter can be opened by the Paraview software. Although we do not share a base case structure, all the steps used to perform the simulations are given below. On the Octave folder, the user will find three different sets of codes. Each set can be used to analyze each one of the simulation steps in order to validate the entire CFDEM simulation. The instructions on how to use the codes are described in each set within the InputData.m file. 1) First the user needs to run a pure CFD simulation of a simple channel flow using a large-eddy model (in our case the WALE model). The simulation must be performed unitl fully-developed turbulence is reached. The final results can be stored in the case by reconstructing the final time-step of the CFD simulation. We suggest checking the "channel395" tutorial from the OpenFOAM tutorials folder as a base case. 2) The Octave code CFD_Analysis can be used to plot the mean velocity profiles and the components of the Reynolds stress in order to compare the results with DNS ones, and to check the validity of the mesh. The mesh used in step (1) must be also used in the subsequent steps. 3) Afterward, the user must build a CFD-DEM simulation where the grains are allowed to fall freely in stationary water, until a conical heap is formed. These results are stored in LIGGGHTS within a restart file. 4) Finally, the user must include into de "zero" folder (from the CFD side) the results stored from step (1) and restart the simulation stored in step (3). 5) As a post-processing tool, the Octave_Flow and Octave_Traj, can be used to analyze both the flow over the dune and the particles motion and forces, respectively.

Institutions

Universidade Estadual de Campinas, University of California Los Angeles Department of Atmospheric and Oceanic Sciences

Categories

Dunes, Computational Fluid Dynamics, Discrete Element Method

License