Fanning factor

Pressure drop is important to quantify the process energy requirements and can even be the limiting factor in the design and performance of a monolith reactor. It is related to Darcy s friction factor (four times higher than the Fanning factor) by [41]... 

The problan formulation consists of applying the Bernoulli equation to the three different pipes, with diameters dl, d2, and d3, and a global mass balance at the splitter. The fanning factor for the friction loss is calculated using the Colebrook correlation [5] ... 

Flow in the laminar regime is often characterized by a friction loss factor, which is 64/Re for the Darcy factor or 16/Re for the Fanning factor (this topic wiU be discussed in more details in Chapter 2). As a result, the losses in the laminar regime appear to be a linear function of speed, whereas in the turbulent regime they are proportional to the square of the speed. As we wiU see in Chapter 5, researchers have struggled with special definitions of a modified Reynolds number for non-Newtonian flows. 

The iterated pressure loss is 349.7 Pa/m, which is still higher than the measured 270 Pa/m. For further iteration, the fanning factor must be recalculated ... 

PRINT REVISED FANNING FACTOR = " DFANNEW pressure it = DFANNEW 2 sgm 1000 vl 2/dln... 

IF rt = "Y" OR rt = "y" THEN GOTO 10 LPRINT "REVISED FANNING FACTOR = " DFANNEW... 

Above V. the flow is pseudohomogeneous or symmetric (but not necessarily uniform). With negligible hold-up, Govier and Aziz (1972) proposed to express the pressure loss in terms of the ratio of the friction fanning factor for the slurry mixture and the liquid mixture or as... 

This a fanning factor, so the Darcy friction factor is 0.3248. 

FIGURE 5-4 Values of critical Reynolds number and critical fanning factor versus the flow index n for pseudoplastic slurries based on Equation 5-27. 

Defining as the fanning factor in the laminar regime, and fjds the fanning factor in the turbulent regime, Darby derived the following equations ... 

Since the Darcy friction coefficient is usually accepted as four times the fanning friction coefficient Equation 6-3 for a slurry may be rewritten in terms of the fanning factor As discussed in Chapter 2. 

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