FreeCAD - An open-source parametric 3D modeler
ANSYS Fluent - ANSYS engineering simulation and 3D design software delivers product modeling solutions with unmatched scalability and a comprehensive multiphysics foundation.
SketchUp - 3D for Everyone
OpenFOAM - OpenFOAM® - Official home of The Open Source Computational Fluid Dynamics (CFD) Toolbox.
LibreCAD - An open source 2D CAD application for Windows, Apple and Linux.
Autodesk Fluid Flow - Autodesk Fluid Flow is an industry-leading fluid dynamics software that helps to enhance product performance and reliability.