This module is new in version 4.2a. The Particle Tracing Module is a general purpose, flexible tool that allows you to trace the trajectories of particles in the presence of an external field.

The Particle Tracing Module includes the following physics interfaces:

  • Mathematical Particle Tracing:
  • Specify the equations of motion using massless, Newtonian, Lagrangian, or Hamiltonian formulations.
  • Complete freedom over the equations makes it possible to model ray tracing, for example.
  • Charged Particle Tracing
  • Use this interface to model ion and electron trajectories in electric and magnetic fields
  • This interface make it easy to define electric, magnetic, and collisional forces
  • Particle Tracing for Fluid Flow
  • Use this interface to model microscopic and macroscopic particles in a fluid
  • Includes drag, gravitational, dielectrophoretic, acoustophoretic, and many other forces.

For visualization of the results two new plot types are available:

  • Poincaré Map: You can use a Poincaré Map plot for 2D and 3D models to visualize particle trajectories in a section that is transversal to the particle trajectories.
  • Phase Portrait: You can use a Phase Portrait plot for 2D models to visualize large data sets of particle trajectories. A phase portrait is a geometric representation of the particle trajectories in the phase plane.

All of the interfaces provide many different ways of releasing particles, either on the boundary or domain level. Particles can also be released at multiple different times. There are several options available for describing how the particles interact with the wall, including specular reflection. The interfaces can all be used with COMSOL Multiphysics but tracing charged particles benefits from the AC/DC Module because it makes it possible to model complex alternating or direct current systems. Similarly, tracing particles in a fluid system benefits from the CFD Module or the Microfluidics Module due to the number of advanced fluid flow features available in those modules.