Use the Particle Properties node to specify the particle mass and charge number when using the
Newtonian or
Newtonian, first order formulation. Specify the particle velocity when using the
Massless formulation.
This section is shown when Newtonian or
Newtonian, first order is selected as the
Formulation. Choose an option from the
Particle species list. The default is
User defined, allowing the mass and charge number to be specified directly. The remaining options are detailed in
Table 4-2. The values in the
Mass column show the numeric values of the particle mass, as well as any built-in physical quantities for the masses of these species.
Enter a value or expression for the Particle mass mp (SI unit: kg). The default expression is
me_const, which is a predefined constant within COMSOL Multiphysics
for the electron mass,
9.10938356 × 10−31 kg.
If the Relativistic correction check box is selected in the physics interface
Advanced Settings section, instead specify the
Particle rest mass mr (SI unit: kg). The default expression is
me_const.
Enter a value for the Charge number Z (dimensionless). The default is
−1 corresponding to the charge number of an electron.
Enter a vector for the Particle velocity v (SI unit: m/s) based on space dimension. The
Massless formulation means that the particles follow streamlines of the particle velocity expression.