Date of Award
Doctor of Engineering Science in Mechanical Engineering
Hans E. Pawel
Robert P. Kirchner
John Vincent Droughton
The deposition of particles in a parallel-plate channel and a circular tube under the influence of inertia, fluid viscosity, gravity and electrostatic image forces was studied by analytical and numerical methods. A laminar flow with uniform and parabolic velocity profiles was investigated with a particle initial velocity of zero as well as that of the local fluid velocity.
The governing equations were solved by the Lagrangian approach to obtain the particle trajectories from which the fraction of deposition was calculated. Closed form solutions for particle trajectory and a complete deposition of particles in a finite length of the flow passage were obtained for the gravity force alone. When both gravity and image forces are present, the deposition increases greatly. However, a complete deposition cannot be attained, theoretically, in a finite length of the flow passage due to the balance of the downward gravity force and the upward image force in the flow field.
In general, the particle deposition is high for particles with small inertia forces and high image forces. It is also higher for uniform flow than for a parabolic flow and is higher for particles with zero initial velocity than that for particles with the initial velocity of the local fluid.
Chen, Win-Chung, "Deposition of particles in tubes due to gravity and electrostatic charges" (1986). Dissertations. 1212.