Fluid and Particle Dynamics

Thermodynamics Hendrick C. Van Ness, Michael M. Abbott Heat and Mass Transfer James G. Knudsen, Hoyt C. Hottel, Adel F. Sarofim, Phillip C. Wankat, Kent S. Knaebel Fluid and Particle Dynamics Janies N. Tilton Reaction Kinetics Stanley M. Walas... 

James N. Tilton, Ph.D., P.E., Senior Consultant, Process Engineering, E. I. duPont de Nemours Co. Member, American Institute of Chemical Engineers Registered Professional Engineer (Delaware) (Section 6, Fluid and Particle Dynamics)... 

Figure 4-48. Pressure drop for cyclone separator system. Adapted by permission, Lapple, C. E., Fluid and Particle Dynamics, 1st Ed., University of Delaware, 1954.

There are several approaches to developing the correct scaling relationships. Probably the most straightforward is the nondimensional-ization of the governing equations. If we can write the proper equations governing the fluid and particle dynamic behavior, we can develop the proper scaling relationships even if we can t solve the equations (at present we can t). In essence, if a model is designed which follows the... 

From the standpoint of collector design and performance, the most important size-related property of a dust particle is its dynamic behavior. Particles larger than 100 pm are readily collectible by simple inertial or gravitational methods. For particles under 100 pm, the range of principal difficulty in dust collection, the resistance to motion in a gas is viscous (see Sec. 6, Fluid and Particle Dynamics ), and for such particles, the most useful size specification is commonly the Stokes settling diameter, which is the diameter of the spherical particle of the same density that has the same terminal velocity in viscous flow as the particle in question. It is yet more convenient in many circumstances to use the aerodynamic diameter, which is the diameter of the particle of unit density (1 g/cm3) that has the same terminal settling velocity. Use of the aerodynamic diameter permits direct comparisons of the dynamic behavior of particles that are actually of different sizes, shapes, and densities [Raabe,/. AirPollut. Control Assoc., 26,856 (1976)]. 

Principles of fluid and particle dynamics in the respiratory tract (physical and anatomical parameters) are also discussed, as they are the starting point for the development of drug products for inhalation. In fact, they set the conditions used for in vitro and in vivo testing of inhalation systems and define the specifications for new inhalation systems. 

Although much progress has been made in the last decade regarding operation, design and scale-up of spin-filters, in most works found in the literature either fouling or retention problems (or both) were observed. A better comprehension of the fluid and particle dynamics involved in spin-filter perfusion would improve this situation. In this context, a valuable tool that could be used is computational fluid dynamics (CFD), which has been recently employed for the design and performance prediction of other cell separation devices [46,114]. 

Application of the momentum equation to ejectors of other types is discussed in Lapple (Fluid and Particle Dynamics, University of Delaware, Newark, 1951) and in Sec. 10 of the Handbook. 

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