VirtualFluids - open source parallel LBM solver

This paper accompanies the publication of the open source lattice Boltzmann solver Virtual-Fluids [DOI: 10.5281/zenodo.10283048]. Key features of VirtualFluids are the cumulant collision operator, the ability to run multi-scale simulations based on compact interpolation grid refinement and its implementations for both massively parallel CPU and GPU systems. The differences in data structure for the different systems are explained in detail. Independence from compute environments is obtained through virtualization. This facilitates portability and simplifies the installation of VirtualFluids. Regression testing is used to guarantee consistency of simulation results over successive releases. Virtualization and regression testing also facilitate the reproducibility of results independent of evolving computational environments.