Effect of Reynolds number

FIG. 22-29 Qualitative effects of Reynolds number and applied-electric-field strength on the filtration permeate flux J. Dashed lines indicate large particles (radial migration dominates) solid lines, small particles (particle diffusion dominates). [Pg.2010]

Fig. 11. Effect of Reynolds number upon eddy conductivity.

The Reynolds analogy is equivalent to setting the turbulent Prandtl number as defined in Eq. (24) equal to unity. Figure 13 shows the effect of Reynolds number upon a space average value of the turbulent Prandtl number (C3, P3, S7). Information presented in Fig. 13 is open to uncertainty since it is based upon measurements for air and represents only the space average value of this ratio throughout the turbulent portion of the stream. The turbulent Prandtl number is undoubtedly a function of position as well as of the Reynolds number for a given stream (PI). [Pg.259]

Figure 11. Effect of Reynolds number on ratio of turbulent to laminar burning velocity for hydrocarbon-air flames. Constant density and viscosity (8)...

FIGURE 6 Effect of Reynolds number on blend number, ON, for the two impellers shown. 0, blend time N, impeller rotational speed. [Pg.282]

In a horizontal decanter, dispersed phase drops are being carried along the decanter by the flow of the continuous phase. If the velocity of the two separated layers is more than a few centimeters per second, the shape of the dispersion zone will be distorted by drag, and there will be entraiiunent of drops [21], Therefore, the Reynolds number for both phases must be limited. The effect of Reynolds number on liquid-liquid separation is shown in Table 6.14. This hmitation on the Reynolds number will also be used for the dispersed phase to determine the decanter diameter. The minimum diameter is 10.0 cm (0.328 ft) because of wall effects [19]. [Pg.308]

Pedinotti, S., Mariotti, G., and Baneijee, S., Effect of Reynolds number on particle behavior near walls in two-phase turbulent flows. Proc. 5th. Int. Symp. Flow Mod. Turb. Meas., Paris, Presses Pont et Chausees, 425 (1993). [Pg.325]

When natural convection is controlling the effect of Reynolds number is unimportant, and the general expression reduces to... [Pg.385]

The effect of Reynolds number on the activity and effectiveness factor is shown in Figure 5 for ki = 8000 mole / 1-h and T = 503 K. In this figure the effectiveness factor reduction defined... [Pg.315]

The effect of Reynolds number is clearly displayed in Fig. 8.10. When the upstream region is included the entry length is much shorter (LJd = 0.1264 rather than 0.43) since the velocity has already rearranged somewhat upstream. [Pg.195]

In adiabatic frictional flow, the temperature of the gas changes. The viscosity also varies, and the Reynolds number and friction factor are not actually constant. In gas flow, however, the effect of temperature on viscosity is small, and the effect of Reynolds number on the friction factor / is still less. Also, unless the Mach number is nearly unity, the temperature change is small. It is satisfactory to use an average value for /as a constant in calculations. If necessary,/ can be evaluated at the two ends of the conduit and an arithmetic average used as a constant. [Pg.133]

The effect of Reynolds number on the fouling resistance is also shown on Fig. [Pg.131]

Belmar-Beiny, M.T., Gotham, S.M., Fryer, P.J. and Pritchard, A.M., 1993, The effect of Reynolds number and fluid temperature in whey fouling. J. Food Eng. 19, 119-139. [Pg.473]

The remarkably small effect of Reynolds number indicated by Eq. (198) is well borne out experimentally. The torque on rotating bodies has been extensively studied in connection with power requirements for mixers, agitators, and similar devices. In the so-called laminar regime, logarithmic plots of the dimensionless Power number... [Pg.360]

Warholic, M. D., Massah, H., and Hanratty, T. J., Influence of drag-reducing polymers on turbulence effects of Reynolds number, concentration and mixing, Exp. Fluids, 27,461-472 (1999a). [Pg.126]

One of the most important relationships for single-phase flow studies is the effect of Reynolds number on the heat transfer rate. The Reynolds number Re = UodtDA was calculated for each Sow velocity. Figure 11 shows the effect of the Reynolds number on single-phase heat... [Pg.247]

Fignre 11 Effect of Reynolds number on single-phase flow beat transfer. [Pg.248]

A Three-Dimensional Finite-Element Analysis of the Effect of Reynolds Number on Extrudate Swell of Newtonian Liquids from Dies... [Pg.349]

Little has been published on the effect of Reynolds number on extrudate swell of liquids from fully three-dimensional dies. However, its effect on two-dimensional extrudate swell of a Newtonian fluid has been well characterized [1-4]. The influence of Reynolds number on the final die swell ratio for both planar jets (i.e., the thickness of the extrudate divided by the width of the channel) and axisymmetric jets (i.e., the diameter of the jet divided by that of the tube) are summarized in Fig. 1. In both cases, swell is greater than 1 for low Reynolds numbers but decreases to values less than 1 at high Reynolds numbers. As Reynolds number approaches infinity, the die swell ratios for the axisymmetric and planar jets approach the asymptotic values of /3/2 and 5/6, respectively [5,6]. [Pg.349]

Extrudate swell from more complicated, three-dimensional dies has been examined to some extent. However, most of these consider a zero Reynolds number situation [7-16]. The only fully three-dimensional die swell analyses including the effects of Reynolds which appear in the literature are those of Newtonian liquids from square dies [17-19]. One experimental study attempted to assess the effect of Reynolds number on extrudate swell from square and rectangular dies [20]. Unfortunately, those results appear to have been obscured by the inability to separate the effects of gravity from those of the Reynolds number [19]. [Pg.350]

Here, the three-dimensional finite-element procedure used by Gifford [19] to solve three-dimensional free-surface problems which include inertia will be reviewed. Previous results of simulations showing the effect of Reynolds number on extrudate swell of Newtonian liquids from a square die are discussed and compared to new results from a rectangular die. Limiting die swell solutions at infinite Reynolds number are discussed and the effect of the aspect ratio of the rectangle on these limiting values is presented. The effect of wall slip on die swell from the square die is also considered. [Pg.350]

In practice, few extrusion dies are designed with square channels at the exit. However, many are designed with a rectangular channel in the lip region exiting the die. The effect of Reynolds number on the extrudate swell from such shapes appears to have been heretofore unreported. [Pg.358]

Gifford, W. A., A three dimensional finite element analysis of the effect of Reynolds number on extrudate swell of Newtonian liquids from square dies, Can. J. Chem. Eng. 77 161-167 (1993). [Pg.366]

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