WaLBerla: HPC software design for computational engineering simulations

WaLBerla (Widely applicable Lattice-Boltzmann from Erlangen) is a massively parallel software framework supporting a wide range of physical phenomena. This article describes the software designs realizing the major goal of the framework, a good balance between expandability and scalable, highly optimized, hardware-dependent, special purpose kernels. To demonstrate our designs, we discuss the coupling of our Lattice-Boltzmann fluid flow solver and a method for fluid structure interaction. Additionally, we show a software design for heterogeneous computations on GPU and CPU utilizing optimized kernels. Finally, we estimate the software quality of the framework on the basis of software quality factors.

► We show software designs concepts for massively parallel numerical simulations.
► The Sweep concept breaks down numerical algorithms into work steps.
► A Patch concept enables efficient parallelization.
► Functionality management allows for heterogeneous simulations.
► Software quality factors maintainability, expandability and efficiency are improved.