This book presents cutting‑edge research from the 14th ERCOFTAC Workshop on Direct and Large Eddy Simulation, offering a unified look at how high‑fidelity computational methods are being used to investigate complex flow phenomena across aerodynamics, compressible and multiphase flows, combustion, and turbomachinery. It highlights studies that apply DNS and LES to real‑world challenges—such as analyzing vehicle aerodynamics, understanding shock‑wave and turbulent boundary‑layer interactions, modeling particle‑laden flows with advanced data‑driven breakage models, and exploring how turbulent spray flames influence nanoparticle synthesis—while also presenting foundational advances in turbulence modeling, statistical analysis, and numerical methods like remeshed vortex techniques.