Internal flow characteristics

One proposed simplified theory (4) provides reasonably accurate predictions of the internal flow characteristics. In this analysis, conservation of mass as well as angular and total momentum of the Hquid is assumed. To determine the exit film velocity, size of the air core, and discharge coefficient, it is also necessary to assume that a maximum flow through the orifice is attained. 

The Reynolds number is sufficient as a parameter for describing the internal flow characteristics, such as discharge coefficient, air core ratio, and spray angle at the atomizer exit. 

Cross Wind and Internal Flow Characteristics of Dry Cooling Towers Russell, C. M. B. McChesney, H. R. Holder, D. W. Jones, T. V., Verlinden, M. 

N. K. Rizk, A. H. Lefebvre, Internal flow characteristics of simplex swirl atomizers, AIAA J. Propuls. Power 1(3), 193-199 (1985a). 

The ROTOBERTY internal recycle laboratory reactor was designed to produce experimental results that can be used for developing reaction kinetics and to test catalysts. These results are valid at the conditions of large-scale plant operations. Since internal flow rates contacting the catalyst are known, heat and mass transfer rates can be calculated between the catalyst and the recycling fluid. With these known, their influence on catalyst performance can be evaluated in the experiments as well as in production units. Operating conditions, some construction features, and performance characteristics are given next. 

Arcoumanis, C., Martinez-Botas, R.F., Nouri, J.M., and Su, C.C., 1997. Performance and Exit Flow Characteristics of Mixed Flow Turbines, International Journal of Rotating Machinery, 3(4) 277-293. 

Z. Ropiolek, S. Mierzwinski, M. Hurnik, j. Wojciechowski. Air flow characteristic in scale models of room ventilation. In Roomvent 9H Proceedings of the 6th International Conference on Air Distribution in Rooms, vol. 1, pp. 287-293.. Stockholm, Sweden, 1998. 

Ide H, Kawahara A, Kawaji M (2006) Comparison of gas-liquid two-phase flow characteristics between mini-channels and micro-channels. In Proceedings of 13th International Heat Transfer Conference, Sydney Convention and Exibition Centre, Sydney, Australia, 13-18 August 2006, MPH-51... 

Shear cell measurements offer several pieces of information that permit a better understanding of the material flow characteristics. Two parameters, the shear index, n, and the tensile strength, S, determined by fitting simplified shear cell data to Eq. (6), are reported in Table 2. Because of the experimental method, only a poor estimate of the tensile strength is obtained in many cases. The shear index estimate, however, is quite reliable based on the standard error of the estimate shown in parenthesis in Table 2. The shear index is a simple measure of the flowability of a material and is used here for comparison purposes because it is reasonably reliable [50] and easy to determine. The effective angle of internal... 

The influence of consolidation load on the flowability of sucrose is shown in Fig. 8. For this material, the effective angle of internal friction is nearly constant yet the shear index is seen to change with state of consolidation. Apparently, for sucrose, increased consolidation results in a somewhat more free flowing although still cohesive material. As such, sucrose can be considered a complex powder [49] with perhaps somewhat better flow characteristics when consolidated (as might occur in a hopper). 

The flow rate-pressure drop measurements shown in Table 3.1 were made in a horizontal tube having an internal diameter d, = 6 mm, the pressure drop being measured between two tappings 2.00 m apart. The density of the fluid, p, was 870 kg/m3. Determine the wall shear stress-flow characteristic curve and the shear stress-true shear rate curve for this material. 

If the fluid flows in two pipes having internal diameters dti and dt2 with the same value of the wall shear stress in both pipes, then from equation 3.17 the values of the flow characteristic are equal in both pipes ... 

Winkelmann D, Thonon B, Auracher H, Bontemps A. Two-phase flow characteristics of a corrugated channel. Proceedings of the 20th International Congress of Refrigeration, IIR/IIF, Sydney, 1999. 

The characteristics of electrokinetically controlled fluid flow in microchannel manifolds has been studied in a systematic way by Harrison and coworkers [28, 30]. An illustrative demonstration of the potential of this approach is shown in Fig. 2 for the controlled dilution of a fluorescein solution under voltage control. In parallel with a stepwise decrease of the potential applied to the fluorescein reservoir, a decrease of fluorescence signal downstream after the junction is visible in Fig. 2. As long as the ionic strength and pH in each supply channel is the same (same jieo), mass balance is automatically fulfilled, and the incoming flows at the intersection will be exactly balanced by the outgoing flow of the mixed components (otherwise, mass balance would be enforced by additional hydrodynamic or secondary internal flows). This way of mixing fluids was also... 

Flow characteristics can be regulated by the incorporation of fillers, by the use of scrims or woven tapes as internal shims within the adhesive itself, or by the careful regulation of the cure cycle. All these options along with a few more are available to the adhesive for-mulator and end user. Generally, fillers are incorporated to control the viscosity of the adhesives as well as other properties such as thixotropy and sag resistance. 

A flow having some characteristics of both an external and an internal flow. 

External flows involve a flow, that is essentially infinite in extent, over the outer surface of a body. Internal flows involve the flow through a duct or channel. It is not always possible to clearly place a convective heat transfer problem into one of these categories since some problems have several of the characteristics of both an internal and an external flow. An example of such a case is shown in Fig. 1.7. 

Figure 4.22 shows the flow characteristics for standard ATDs and the iLEC ATD. The reduced diameter of internal couplers and vessel adapters for the standard ATDs accounts for more than 70 percent of the permeate-tube pressure drop in some systems.26 The interlocking iLEC ATD design eliminates these restrictions, imposing less permeate backpressure, resulting in lower operating pressure requirements. 

Channels filled with a single-particle string have much better solid flow characteristics than a packed bed, and so application of monoliths as moving-bed reactor internals is appealing. This structured moving-bed reactor design opens a wide range of applications. 

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