Electrohydrodynamic (EHD) flow, charged particle behaviours and the interaction between the two phases were investigated in a wire-duct electrostatic precipitator (ESP) with Star-shaped electrode by employing a coupling numerical model of the EHD flow and charged particle dynamics. The model used the finite volume method to solve the electric field equation and the space charge equation, which couple with the FLUENT turbulence model, including the charged particle motion equation by the Lagrangian method, and the flow patterns and particle behaviours in the star-shaped ESP at three inlet velocities were simulated in detail. The secondary flow in the Star-shaped ESP channel has a significant effect on the flow pattern and particle concentration distribution. The influence of secondary flow on the flow pattern is more obvious as the inlet velocity decreases. The effect of secondary flow on particle behaviour is more evident for fine particles. The vortexes produced by secondary flow affect the particle behaviour by affecting the mainstream flow. The vortexes near the collecting wall squeeze the particle flow away from the wall, while the vortexes in the downstream of the discharge electrode promote the particle flow toward the collecting wall. The collection efficiency, especially the efficiencies of submicron sized particles, can not be estimated correctly by the Deutsch formula as the strong secondary flow exists in the ESP channel.
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