waLBerla (widely applicable Lattice-Boltzmann from Erlangen) is an open-source software framework developed at Friedrich-Alexander University Erlangen-Nürnberg (FAU) in Germany, designed primarily for fluid dynamics simulations using the lattice Boltzmann method (LBM). Its modular architecture allows for easy integration of new models and solvers, making it adaptable to various scientific and engineering applications beyond fluid dynamics. Optimized for high-performance computing (HPC), waLBerla is capable of large-scale, multi-physics simulations, including fluid-structure interactions, and is designed to scale efficiently across thousands of processors. GPU support, combined with automatic code generation through lbmpy, enables GPU-compatible C++ code for supported LB schemes and methods, further enhancing waLBerla’s performance on modern hardware.

The framework’s versatility extends to applications in fluid dynamics, biomedical engineering, materials science, and environmental science, making it a valuable tool for modeling everything from blood flow to pollutant dispersion. waLBerla’s extensive documentation and active user community support new and advanced users alike, fostering continuous development and collaboration. With contributions from researchers worldwide, waLBerla continues to evolve, addressing the latest scientific challenges and offering a powerful solution for complex simulations.