Aerodynamic principle

This chapter describes the aerodynamic principles, models, and equations that govern the flow and the contaminant presence and transport in a designated volume of a work room. The purpose of local ventilation is to control the transport of contaminants at or near the source of emission, thus minimizing the contaminants in the workplace air. 

FALLOUT (Radioactive . The term fallout generally has been used to refer to particulate mutter that is thrown into the atmosphere by a nuclear process of short time duration. Primary examples are nuclear weapon debris and effluents from a nuclear reactor excursion. The name fallout is applied both to matter that is aloll and to matter that has been deposited on the surface of the earfh. Depending on the conditions of formation, this material ranges in texture from an aerosol to granules uf considerable size. The aerodynamic principles governing tls deposition are the same as for any Other material of comparable physical nature that is thrown into the air. such as volcanic ash or particles from chimneys. Therefore, many of the principles learned in. studies of fallout from nuclear weapons can be applied lo studies of other particulate pollution in the atmosphere. 

Dixit, R. and Puthli, S., Fluidization technologies Aerodynamic principles and process engineering, J. Pharm. 

The principle of inertial impaction is employed to sample aerosols aerodynamically for characterization of particle size and will be dealt with theoretically later in this chapter. 

Due to the fact that Hugoniot was the first to formulate the laws of the resistance of air to the flight of projectiles, he is generally considered as the founder of the modem science of "aerodynamics. The principles of aerodynamics are also applied to aeronautics... 

Thus it could be interesting to find another technology of aerodynamic type, which would enjoy the potential of efficiency increase and has more clear understanding of its principles. 

Separation in these devices known as winnowing machines [3], is achieved due to the difference between trajectories of coarse and fine particles in the separation zone (Fig. lb). Their operation and efficiency are strongly affected by the stochastic factors of the process, in particular by uncertainties in feeding and particles aerodynamic interactions. In most cases coarse particles prevent proper classification of fines. Separation efficiency of these devices is usually low. They are normally used for separation of solid particles according to densities (e.g. grain from peel), rather than by size. Sometimes crossflow separation in horizontal streams is used in combination with other separation principles. 

Potential mechanical problems associated with mechanically variable geometry combustors have promoted studies on various types of aero-dynamically modulated combustors. This modulation of the combustor could, in principle, be controlled by very small control flows introduced or extracted from the chamber of the combustor. Alternatively, it could be inherent in the aerodynamics of the combustor. Flexibility in combustor operation can be obtained easily by small changes in combustor geometry so as to obtain the desired aerodynamic changes within the combustor. It can also be obtained by changing the stoichiometry of the flow. 

Fig. 9.22 (a) Schematic view of E-Spart relaxation cell (b) principle of particle measurement. Individual particles are subjected to acoustic and/or electric excitation and the resultant response is measured by LDV to determine aerodynamic size and electrostatic charge. 

Beginning with Olivier,a number of authors have tried to develop meteor theories based on first physical principles.The physics of the body is of fundamental importance with respect to the dynamical aspects of the meteor problem discussed above. It concerns the rapidly varying flow-regime with the possible eventual formation of a shock wave, and describes the meteroid heating that leads to ablation, fragmentation, melting and vaporization. This aerodynamic aspect of the problem will not be discussed in depth. The extreme environmental dynamics of the problem, however, have many similarities with Chaps. 2 of Raz and Levine and 3 of Boyd in this book. Extensive treatises specific to meteor dynamics are found in the reviews by Bronshten and Ceplecha et cd. °... 

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