Use the Charge Accumulation node to compute the charge accumulation on a particle immersed in a gas background with free ions as a function of time.
Enter a value or expression for the Temperature T (SI unit: K). The default value is 293.15 K. If a physics interface that computes the gas temperature is present, then this can be selected from the list as a model input.
Enter a value or expression for the Pressure p (SI unit: Pa). The default value is 1 atm. If a physics interface that computes the gas pressure is present, then this can be selected from the list as a model input.
Enter a value for the Initial accumulated charge number Z
a,j (dimensionless). The default is 0.
Select as option from the Particle electric properties list:
Dielectric (the default), or
Conductive. If
Dielectric is selected, enter a value for the
Particle relative permittivity εr,p (dimensionless) in the settings for the
Particle Properties node.
Enter a value or expression for the Space charge density ρq (SI unit: C/m
3). The default value is 10
-5 C/m
3. If a physics interface that computes the space charge density is present, then this can be selected from the list.
If the charging model Lawless,
Classical diffusion,
Classical field,
or
Classical diffusion and Field is selected from the
Particle charging model list, enter a value or expression for the
Reduced ion mobility μiN (SI unit: 1/(Vms)). The default value is 3
× 10
21 1/(Vms).
Enter a value or expression for the Ion Temperature Ti (SI unit: K). The default value is 293.1 K.
If the charging model White is selected from the
Particle charging model list enter a value or expression for the
Ion Mass Mi (SI unit: kg/mol). The default is 100 g/mol.