This investigation was made to determine the effect on the deposition of fine particles in a vertical channel and in a vertical tube due to the influences of electrostatic charge, diffusion, and gravity acting in the direction of flow. The flow considered was laminar, incompressible and steady.
The governing equations for the fluid phase were derived from the Navier-Stokes equation and the continuity equation while the equations for the particle phase were derived from Poisson's potential equation and the continuity equation. Since the governing equations are non-linear partial differential equations the solutions were developed using numerical methods.
The flow patterns considered were uniform, developing and fully developed with symmetry about the axis of the channel or tube.
For the case of the vertical tube, it was found that the deposition depends on the velocity ratio of terminal velocity to the average fluid velocity and decreases with increasing velocity ratio. The curves for the fraction of deposition at any velocity ratio were found to fall between that for uniform flow and that for fully developed flow due to diffusive effect alone when a proper dimensionless distance was used.
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