Speaker
Description
Wave-based simulation methods are well suited for analyzing acoustic problems in which wave phenomena such as diffraction and scattering play a dominant role. Among these, the finite-difference time-domain (FDTD) method is a robust and versatile approach.This work presents CRUNA, an open-source 3D FDTD solver with an integrated optimization framework based on adjoint gradient computation.While the modular codebase addresses a wide variety of flow-related problems, this contribution focuses on the acoustic and aeroacoustic components of the solver and their application to wave propagation and optimization tasks.The solver supports several sets of governing equations, ranging from linearized acoustic formulations to more comprehensive aeroacoustic models. It provides explicit time-stepping schemes, as well as explicit and implicit spatial discretization methods. CRUNA is highly parallelized to enable fast execution in high-performance computing environments. Non-reflective characteristic boundary conditions are implemented, and immersed boundary methods based on effective volume and flow resistivity enable an accurate representation of complex geometries and impedance boundaries.Representative examples demonstrate the framework, including aeroacoustic simulations, sound source localization and synthesis, and pinna-related transfer function computations. By providing CRUNA as open-source software, this work aims to support transparency, reproducibility, and further development within the computational acoustics community.