Example:

using design data

Given:

Rn = V = 3.48 ft per/sec

D = .53 ft

Y = .0000128 ft/sec

V = Q = 3.48 x .53 = 1.8444

= 144093.75

A

.0000128

.0000128

= 144094 or 1.44 x 10 to the 5th

have calculated it?

operations because it has a telescoping effect on the product and

causes an increase in the spread of the interface.

the interface to a minimum.

In laminar flow the Reynolds number is 2,000 or below, in turbulent flow the

Reynolds number is 4,000 and above. The numbers between 2,000 and 4,000 are

considered transition flow.

calculating the Reynolds number and changing to scientific notation, we can

obtain a friction factor using Figure 1-2. Horizontally across the bottom

are numbers in scientific notation, to the right and vertically is pipe

diameters, to the left of the graph and vertically are the friction factors

starting at .010 and ending with .032. Using our calculation 1.44 X 10 to

the 5th, locate this on the bottom horizontal line. The pipe diameter is

6.415 inches; move up the chart until the line intersects the pipe diameter

curve and move to the left and read .0188 for the friction factor.

The Darcy Weisbach equation provides an accurate method of calculating

friction head loss in a pipeline. This equation should be used when a high

degree of accuracy is required. An example would be the construction of a

permanent pipeline system. The Darcy Weisbach equation states that:

Where:

Hf = friction head loss, in ft

f = dimensionless friction factor

V = velocity, in ft/sec

g = acceleration due to gravity (32.2 ft/sec)

d = inside diameter of the pipe, in ft

L = length of pipe, in ft

Hf = fxLxV

2g x d

12-12

QM 5099