NVIDIA Isaac Sim is an open-source application on NVIDIA Omniverse
CFDTool - Easy to Use Computational Fluid Dynamics (CFD) Toolbox
FEATool Multiphysics is an easy-to-use FEA and CFD Simulation Toolbox
Static and Dynamic Structural Analysis of 2D and 3D frames.
Free multiphysics simulation software package
Open Knowledge on engineering development.
collection of illustrative programs:small games, simulators: C, Matlab