Bidirectionally Coupled Particle Tracing
The Bidirectionally Coupled Particle Tracing study ()¨is used to model the interactions of particle trajectories with stationary fields. The study creates a Time-Dependent Solver that solves for all degrees of freedom related to the particles. All other degrees of freedom are computed using a Stationary Solver. The two solvers are repeated using a For-End For loop so that a self-consistent solution is obtained, taking the bidirectional coupling between the moving particles and stationary fields into account.
See the Time Dependent study step and Common Study Step Settings for information about the following sections: Study Settings, Results While Solving, Physics and Variables Selection, Values of Dependent Variables, Mesh Selection, and Study Extensions.
Iterations
Select an option from the Termination method list: Fixed number of iterations (the default) or Convergence of global variable. For Fixed number of iterations enter a positive integer for the Number of iterations (default 5). Any nodes between this For node and the following End For node will be repeated a number of times equal to the specified Number of iterations.
For Convergence of global variable enter the following:
Global variable (default 1)
Relative tolerance (default 0.001)
Maximum number of iterations (positive integer, default 25)
Minimum number of iterations (positive integer, default 1)
This default solve sequence generated by this study step includes a loop containing the For and End For nodes. The options in this section correspond to the General section of the settings window for the For node.
Using the Bidirectionally Coupled Particle Tracing Study Step
In electromagnetics, this study step is used to model particle beams at constant current that are affected significantly by self-fields. In other words, the charge density and current density of the charged particle beam are significantly large enough that they contribute to the electric and magnetic fields in the surrounding domain enough to noticeably perturb the particle trajectories. When tracing particles in a fluid, this study step is used to model the effects of the drag force exerted on the particles and the corresponding body load exerted on the fluid by the particles. This study is available with the Particle Tracing Module.