A model coupling gas phase

electric field and particle phase was established to study the motion characteristics of charged particles in a diesel particulate detection device. The model was solved by the COMSOL Multiphysics software

and the motion track and velocity of as well as the force on the charged particles inside the diesel particulate detection device were obtained. The results show that under electric field force

the charged particles move towards the grounding plate and shifted from the original track. As a high voltage is applied to the ionization-charge region

and a square wave voltage to the electrostatic trapping region

the square wave current appears in the measurement region

achieving the conversion of particle concentration. The particle motion is slow and stable near the ionization-charge and electrostatic trap regions

making particles be fully charged in the ionization-charge region

and some particles be trapped in the electrostatic trap region. In the ionization-charged and electrostatic trapping zones

particles are affected by the electric field and the drag forces

and the drag force increases to some extent with the increase of the inlet flow velocity.