Fluid flow patterns

In aerosol theory, is the velocity of free fall of a particle, and by extension in the current work is an empirical velocity related to the buoyancy of the contaminant in air. We further assume that the overall fluid flow pattern is unaffected by the minor quantity of the buoyant contaminant. 

The above considerations give us a technique for estimating the required jet momentum and outlet flow rates. Other important parameters are the heights of the inlet and outlet apertures. The choice of these parameters will not, in general, have a significant effect on the overall fluid flow pattern and the resulting distribution of the contaminant, and these should be chosen to optimize the performance of the inlet and exhaust pumps. 

Figure 5-23B. Fluid flow pattern for propeller mounted center with baffles, axial flow pattern. By permission, LIghtnin (formerly Mixing Equipment Co.), a unit of General Signal.

Figure 10-21 A. Impingement baffles and fluid-flow patterns. (Used by permission Brown Root, Inc.)...

This applies regardless of the fluid flow pattern in the uniti . Such a unit could be like the one shown in Figure 10-IC also see Figure 10-29B. 

The extension of generic CA systems to two dimensions is significant for two reasons first, the extension brings with it the appearance of many new phenomena involving behaviors of the boundaries of, and interfaces between, two-dimensional patterns that have no simple analogs in one-dimension. Secondly, two-dimensional dynamics permits easier (sometimes direct) comparison to real physical systems. As we shall see in later sections, models for dendritic crystal growth, chemical reaction-diffusion systems and a direct simulation of turbulent fluid flow patterns are in fact specific instances of 2D CA rules and lattices. 

Glaser and Litt (G4) have proposed, in an extension of the above study, a model for gas-liquid flow through a b d of porous particles. The bed is assumed to consist of two basic structures which influence the fluid flow patterns (1) Void channels external to the packing, with which are associated dead-ended pockets that can hold stagnant pools of liquid and (2) pore channels and pockets, i.e., continuous and dead-ended pockets in the interior of the particles. On this basis, a theoretical model of liquid-phase dispersion in mixed-phase flow is developed. The model uses three bed parameters for the description of axial dispersion (1) Dispersion due to the mixing of streams from various channels of different residence times (2) dispersion from axial diffusion in the void channels and (3) dispersion from diffusion into the pores. The model is not applicable to turbulent flow nor to such low flow rates that molecular diffusion is comparable to Taylor diffusion. The latter region is unlikely to be of practical interest. The model predicts that the reciprocal Peclet number should be directly proportional to nominal liquid velocity, a prediction that has been confirmed by a few determinations of residence-time distribution for a wax desulfurization pilot reactor of 1-in. diameter packed with 10-14 mesh particles. 

Tinker, T. Proceedings of the General Discussion onHeat Transfer, September, 1951, p. 89. Analysis of the fluid flow pattern in shell and tube exchangers and the effect of flow distribution on the heat exchanger performance, (Inst, of Mech. Eng. and Am, Soc. Mech. Eng.). 

Affects shape of pores and thus fluid-flow patterns. 

Laminar flow Fluid flow pattern at low flow rate and/or high viscosity. 

An interwell chemical tracer study established fluid flow patterns within the pilot. Decline curve analysis showed that TFSA injection recovered more than 8150 +... 

To establish the well drainage boundaries and fluid flow patterns within the TFSA-waterflood pilot, an interwell chemical tracer study was conducted. Sodium thiocyanate was selected as the tracer on the basis of its low adsorption characteristics on reservoir rocks (36-38), its low and constant background concentration (0.9 mg/kg) in produced fluids and its ease and accuracy of analysis(39). On July 8, 1986, 500 lb (227 kg) of sodium thiocyanate dissolved in 500 gal (1.89 m3> of injection brine (76700 mg/kg of thiocyanate ion) were injected into Well TU-120. For the next five months, samples of produced fluids were obtained three times per week from each production well. The thiocyanate concentration in the produced brine samples were analyzed in duplicate by the standard ferric nitrate method(39) and in all cases, the precision of the thiocyanate determinations were within 0.3 mg/kg. The concentration of the ion in the produced brine returned to background levels when the sampling and analysis was concluded. 

Table IV. Tracer Study Established Fluid Flow Patterns Within the Pilot Area...

Fluid flow patterns within the pilot pattern were characterized by an interwell chemical tracer study which showed that as much as 38.4 % of the fluids injected into the pilot flowed out of the unconfined pattern and 75.9 % of the produced fluids are from outside the pattern. 

As mentioned in Chapter 1, the first published work on fluid flow patterns in pipes and tubes was done by Reynolds in 1883. He observed the flow patterns of fluids in cylindrical tubes by injecting dye into the moving stream. Reynolds correlated his data by using a dimensionless group later known as the Reynolds number Re ... 

Figure 7-27 Fluid flow patterns in fixed bed reactors, which allow the variation of velocity profiles within the...

The operation of fluidized beds is connected to fluid mechanics within the beds (Nicastro and Glicksman, 1984). For example, heat and mass transfer are greatly influenced by the solid and fluid flow patterns, which are in turn affected by the bed geometry and internal configuration. Consequently, a thorough knowledge of fluid dynamics is a prerequisite to the successful design of a commercial unit. 

The effect of concentration polarization on specific membrane processes is discussed in the individual application chapters. However, a brief comparison of the magnitude of concentration polarization is given in Table 4.1 for processes involving liquid feed solutions. The key simplifying assumption is that the boundary layer thickness is 20 p.m for all processes. This boundary layer thickness is typical of values calculated for separation of solutions with spiral-wound modules in reverse osmosis, pervaporation, and ultrafiltration. Tubular, plate-and-ffame, and bore-side feed hollow fiber modules, because of their better flow velocities, generally have lower calculated boundary layer thicknesses. Hollow fiber modules with shell-side feed generally have larger calculated boundary layer thicknesses because of their poor fluid flow patterns. 

Despite considerable success in some fields of application, the CFD simulations are still not fully mastered, especially where the considered processes reveal clearly nonhomogeneous, segregated fluid flow patterns. The latter are usually the basic phenomenon in packed or filmlike units used in reactive and non-... 

Figure 3. Fluid flow pattern at the bone surface at maximum compression during the walking cycle.

Figure 4. Canalicular fluid flow pattern within the bone tissue at maximum load during the walking cycle. At the tip of the cutting cone (continuous line), the inflow (resulting from volumetric expansion of the superficial bone layer) changes into an outflow because of volumetric compression of the deeper bone layer. The reversal (indicated by arrow) occurs at a depth of about 10 micrometer. At this depth, canalicular fluid flow will be zero. At the base of the cutting cone (dashed line), high volumetric compression leads to high fluid flow in the canaliculi, which runs towards the resorption tunnel and is maximal near the bone surface.

Different packing geometries result in different and quite complex fluid flow patterns which are of crucial importance for the total process performance. 

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