Characterization of flow

A. Description and Characterization of Flow Networks 1. Graphs and Digraphs... 

Kumar A, Kumaresan T, Joshi JB, Pandit AB (2006) Characterization of flow phenomena induced by ultrasonic horn. Chem Eng Sci 61 7410-7420... 

The chapter begins with a reiteration and extension of terms used, and the types of ideal flow considered. It continues with the characterization of flow in general by age-distribution functions, of which residence-time distributions are one type, and with derivations of these distribution functions for the three types of ideal flow introduced in Chapter 2. It concludes with the development of the segregated-flow model for use in subsequent chapters. 

The characterization of flow by statistical age-distribution functions applies whether the flow is ideal or nonideal. Thus, the discussion in this section applies both in Section 13.4 below for ideal flow, and in Chapter 19 for nonideal flow. 

Several age-distribution functions may be used (Danckwerts, 1953), but they are all interrelated. Some are residence-time distributions and some are not. In the discussion to follow in this section and in Section 13.4, we assume steady-flow of a Newtonian, single-phase fluid of constant density through a vessel without chemical reaction. Ultimately, we are interested in the effect of a spread of residence times on the performance of a chemical reactor, but we concentrate on the characterization of flow here. 

Goranovic, G., Klank, H., Westergaard, C., Geschke, O., Telleman, P., Kutter, J.R, Characterization of flow in laser-machined polymeric microchannels. Micro Total Analysis Systems, Proceedings 5th p7AS Symposium, Monterey, CA, Oct. 21-25,... 

Recognizing this problem, Advances in Chemical Engineering decided to organize the present thematic issue on "Characterization of Flow, Particles and Interfaces to alert the chemical engineering community to this challenging issue. We selected the following six meso-scale measurement technologies. 

Kroitoru, L. (1987) The characterization of flow systems in carbonatic rocks defined by the groundwater parameters Central Israel (Ph.D. diss.), Feinberg Graduate School of the Weizmann Institute of Science, Rehovot, Israel. 

Monceaux, L., Azzi, M., Molodtsof, Y., and Large, J. F. Overall and local characterization of flow regimes in a circulating fluidized bed, in Circulating Fluidized Bed Technology (P. Basu, ed.), p. 147. Pergamon Press, 1986a. 

Chemical engineers have developed very powerful methods for the hydrodynamic characterization of flows in different regimes by using specific apparatus this methodology allows one to model the turbulent flow in industrial or laboratory devices. 

The most used methods for the characterization of flow and species transport inside a porous body include the identification of the characteristics of the pores of the porous structure and the particularisation of classic transport equations to this case. These equations are generally associated with equations describing the solid-fluid interaction, adsorption, capillary condensation and flow due to the capillary forces etc. Concerning the species displacement (flow) problem inside a porous structure, we can consider the following classification ... 

Field flow patterns often differ greatly from what would be expected for uniform fields. Hence, maximum possible characterization of flow before the test site is selected may greatly improve the value of the test. 

Duran, L. and Costell, E. 1982. Rheology of apricot puree characterization of flow. J. Texture Stud. 13 43-58. 

Pan, X., Yu, H., Shi, X., Korzh, V. and Wahland, T. (2007) Characterization of flow direction in microchannels and zebrafish blood vessels by scanning fluorescence correlation spectroscopy. 

Monceaux L, Azzi M, Molodtsof Y, Large JF (1986) Overall and local characterization of flow regimes in circnlating flnidized bed. In CFB Technology, Pergamon press, pp 185-191... 

For industrial high-performance ceramics the transferable characterization of flow properties is indispensable both for developing suitable basic compounds for making complex moulded parts, as well as for designing suitable moulds. 

Giddings, J.C. Yang, F.J. Myers, M.N. Theoretical and experimental characterization of flow field-flow fractionation. Anal. Chem. 1976, 48, 1126. 

P. Pfeifer, A. Wenka, K. Schubert, M.A. Liauw, G, Emig, Characterization of flow distribution in microchannel reactors, AIChE J 2004, SO, 418 25. 

Among various aspects, the characterization of flow pattern transitions and the measurement of pressure drops and heat transfer coefficient have been the main focus of research. Recently, some microscale heat transfer and pressure drop predictive methods havebeenalso proposed. Flowpattern studies havedealt mainly with air-water mixtures. It is important to highlight that in these studies the flow patterns are not a... 

Seguin, D., Montillet, A., Comiti, J. and Huet, F. (1998) Experimental characterization of flow regimes in various porous media. II transition to turbulent regime. Chemical Engineering Science, 53, 3897-3909. 

Drahos J, Cermak J, Guardani R, Schugerl K. Characterization of flow regime transition in a circulating fluidized bed. Powder Technol 56 41-48, 1988. 

The Reynolds number is a characterizer of flow type, being proportional to the ratio of the momentum of the fluid to the viscosity of the fluid. The Reynolds number also accounts for the fact that, whereas increases in momentum tend to push the fluid into turbulent flow, increases in viscosity or increases in viscous forces tend to slow up and straighten out the flow pattern. 

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