Particle Transport, Deposition And Removal From Research To Curriculum Development

Understanding particle transport, deposition and removal are of crucial importance to many technologies such as microelectronic, imaging and pharmaceutical industries. In addition, solving a number of environmental problems requires a detail understanding of particle transport processes. In the last decade, significant research progress in the areas of particle transport, deposition and removal has been made. In this “combined research and curriculum development” project a sequence of two new courses on particle transport, deposition and removal and re-entrainment was developed and an existing course was fully revised to bring these new important research findings to seniors and first year graduate students in engineering. The course materials were made available on the web and the course was taught at two campuses simultaneously. A series of short courses were also offered to industries and at universities and research centers in the US and abroad. Introduction Particle transport, deposition and removal are the key in many technologies that are of critical importance to the competitiveness of US industries, as well as in a number of environmental processes. Last decade has seen development of significant computational as well as experimental tools for studies of particle transport, deposition and removal. The primary objective of this combined research and curriculum development project is to make the fruits of these new important research findings available to seniors and first year graduate students in engineering through developing and offering of sequence of specialized courses. In these courses, the processes of particle transport, deposition and removal and re-entrainment were described. A comprehensive web for these courses was developed, and the courses were taught simultaneously at Clarkson University and Syracuse University. Course Modules These combined research and curriculum development (CRCD) courses are composed of four modules. These are: ‚ Fundamental of particle transport, dispersion, deposition and removal. ‚ Computational modeling of particle transport, deposition and removal. P ge 13961.2 2 ‚ Experimental study of particle transport, deposition and removal. ‚ Industrial applications of particle transport, deposition and removal. The front page of the course web is shown in Figure 1. The lecture notes and the calculations models are uploaded into the course web and are available in both pdf form as well as html form. Figure 1. Front webpage of one of the CRCD courses. Module I, Fundamentals In Module I the descriptions of fundamentals of aerosols including hydrodynamic forces (drag, lift), and adhesion forces were described. The nature of particle adhesion and removal was also discussed. This module also contains the description of particle interaction with laminar flow, Brownian motion process, and particle deposition by diffusion, interception and impaction. The sections on interactions of particles with turbulence and turbulent deposition are normally taught in the second course. Computational modeling of turbulent flows was discussed, and classical models of turbulent deposition were described. In addition the process of aerosol charging and transport under the action of electrical forces and turbulence were presented. P ge 13961.3 3 We have added a number of computational modules to make the course presentations of the materials more interactive. The plan is to have sufficient number of calculation modules for the student to experiment with. As a result the student will develop a physical understanding of some of the more complex concepts. Figure 2 shows a sample of the fundamental module dealing with the lift force acting on a particle in a shear flow. Figure 2. A sample page of the fundamental module on the lift force. Module II, Computer Simulations We refined and developed several computer modules that were incorporated into the course sequence. One class of examples was concerned with exploring the flow and particle transport in a variety obstructed ducts. FORTRAN simulation programs that were developed earlier were converted to JAVA. These programs were incorporated in the modules dealing with the motion of aerosol particles in the obstructed duct flows. The students will be able to interactively use the JAVA Applet programs to explore the effects of various forces (gravity, drag, lift, Brownian), materials properties (particle density), and the flow geometry on the motion and deposition of particles. A module was developed for illustrating Brownian particle motion in cross flows. The flow field in this module is a parabolic velocity profile between two parallel plates. The particle equation of motion includes Brownian motion, drag, lift, and gravity. Figure 3 shows the user interface for this module. Here, particles are injected from a nozzle in the middle of the channel. The dispersion of the Brownian particles can be seen from this figure. The module can also be used to illustrate the effects of the lift force on larger particles. Student can select values of the particle diameter and density, the number of particles, and the centerline fluid velocity. Lift Force