Aerosol characterization turbulence

Specific research subjects have emerged with respect to improved descriptions of specific phenomena. Some time ago, it was speculated that gas-solid interactions and turbulence effects on reaction kinetics would be important areas of advance in the modeling art. Gas-solid interactions include both chemical formation of aerosols and reactions on surfaces of pre-existing suspended particulate matter. Because of differing effects of a material in the gas phase and in some condensed phase, it will be important to characterize transformation processes. The achex (Aerosol Characterization hYperiment) program recently carried out under the direction of Hidy will provide an extensive data base with which to test new ways of treating the gas-solid interaction problem. 

Turbulent agglomeration. Far turbulent agglomeration two cases should be considered. First, if the inertia of the aerosol particles is approximately the same as that of the medium, the particles will move about with the same velocities as associated air parcels and can be characterized by a turbulence or eddy diffusion coefficient DT. This coefficient can have a value 104 to 106 times greater than aerosol diffusion coefficients. Turbulent agglomeration processes can be treated in a manner similar to conventional coagulation except that the larger diffusion coefficients are used. 

Atomization. The main mechanism used for deaggregation of aerosol particles is the atomization process. Various mechanisms, such as a turbulent airstream and ultrasonication, are used in inhaler devices to separate dry particles or create fine liquid droplets. Methods of aerosol generation and the characterization of the various inhalers are available elsewhere [264]. 

The another case of concretion of an aerosol in a turbulent stream is characterized by origination of the inertia differences between corpuscles of different sizes. Owing to turbulence of a corpuscle are sped up till the various speeds depending on a size, and can then face with each other. For a monodisperse aerosol this mechanism has no value. For unequigranular an aerosol with known size distribution of Levich(1959) has shown that speed of concretion is proportional to a basic speed of a turbulent stream in extent 8/3 that is speed of concretion increases very sweepingly with increase in speed of a turbulent stream. As very small corpuscles are sweepingly sped up, value of this mechanism decreases with decrease of a size of corpuscles, and it is the most momentous for corpuscles, whose diameters make 10 10 m. In all cases diffusion of Brouna when diameters of... 

The case of concretion of an aerosol in a turbulent stream, which is characterized by origination of the inertia differences between corpuscles of different sizes is observed. Owing to turbulence of a corpuscle are sped up till the various speeds depending on a size, and can then face with each other. Empirical dependences for calculation of factor of capture of corpuscles calculations on which will well be co-ordinated with experimental data are offered. 

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