OpenFOAM - OpenFOAM® - Official home of The Open Source Computational Fluid Dynamics (CFD) Toolbox.
LTspice - LTspice® is a high performance SPICE simulation software, schematic capture and waveform viewer with enhancements and models for easing the simulation of analog circuits.
ANSYS Fluent - ANSYS engineering simulation and 3D design software delivers product modeling solutions with unmatched scalability and a comprehensive multiphysics foundation.
Circuit Simulator - Animated electronic circuit simulator using ideal components to visualize voltage and current.
MATLAB - A high-level language and interactive environment for numerical computation, visualization, and programming
Solve Elec - Solve Elec is a free educational program to draw and analyze electrical circuits.