VirtualFluids (VF) is a research code developed at the Institute for Computational Modeling in Civil Engineering (iRMB). The code is a Computational Fluid Dynamics (CFD) solver based on the Lattice Boltzmann Method (LBM) for turbulent, thermal, multiphase and multicomponent flow problems as well as for multi-field problems such as Fluid-Structure-interaction including distributed pre- and postprocessing capabilities for simulations with more than 100 billion degrees of freedom.

Getting Started

VirtualFluids is mainly supported on these two platforms:

• Linux
• Windows

VirtualFluids can also be build and used in a Docker image. An ubuntu development environment is located in the container registry. An extensive guide about the usage and development in VirtualFluids with docker can be found here.

The following is a brief explanation of how to use it without Docker:

Software Requirements

• CMake (minimum version 3.15)
• C++ compiler with C++14 support
• Paraview for visualizations (most recent version)

with usage of the GPU:

• CUDA developer.nvidia.com/cuda-zone:
  • Minimum CUDA Version 9.0
  • Minimum Compute Capability 3.0, because of maximal number of Blocks in x direction
  • Recommended Compute Capability 6.0, because of atomics for double precision floating point data (GKS only)

Build VirtualFluids

$ mkdir build && cd build

Pass the relevant options to cmake. E.g. for the CPU part:

$ cmake .. -DBUILD_VF_CPU=ON
$ make

Alternatively enable the options via the cmake-gui.

Options

• BUILD_VF_CPU
  • Build VirtualFluids CPU variant
• BUILD_VF_GPU
  • Build VirtualFluids GPU variant
• BUILD_VF_UNIT_TESTS
  • Build VirtualFluids unit tests
• BUILD_VF_DOUBLE_ACCURACY
  • GPU change between Double and Single Precision

Result Files

The output files can be found in <build directory>/bin/output. As there is an usually high amount of data, you might want to change the output path in the main function.

The CPU part generates a set of multiple output directories in the prescribed output path. The flow fields can be found in the mq directory. To view the flow fields, it is most conveniant to open the mq_collection.pvd file in Paraview. The bc directory contains the boundary condition information, the geo directory contains information on the geometry of the flow domain and the blocks directory contains the block grid.

A GPU computation generates a the time series of output files directly in the output path. In Paraview these time series can be read directly.

Contributing

To contribute to VirtualFluids please follow these instructions.

Documentation

The doxygen generated documentation can be found here.

Known Issues

If you notice any problems on your platform, please report an issue.

Authors

A list of the developers of VirtualFluids is available here.