The Electrostatics Model
Electrostatic force is a force between particles exerted due to their charge, and can be either attractive or repulsive. Since the EDEM Electrostatic model uses Electrostatic screening, the size of a screen must be specified when using this model. Particles outside the screen will be removed from electrostatic force calculations on the central particle as shown:
The screened Coulomb force F_{s} is defined as:
where q1 and q2 are the charges of two particles, r is the distance between their centres, and ε0 is the permittivity of free space (8.854 X 10-12 Fm-1). κ is an inverse of the Debye length, λD.
- q_{e} is the charge of an electron (1.602 X 10^{-19}C)
- ε is the relative permittivity of the medium. EDEM uses a value of 1, which is a relative permittivity of a vacuum.
- K_{b} is the Boltzmann’s constant equal to 1.38 X 10^{-23} JK^{-1}.
- T is the temperature in Kelvin. EDEM uses a value of 295.4K.
- The last term is the local charge concentration (where n is the number of particles of charge z).
(c) 2023 Altair Engineering Inc. All Rights Reserved.