not represent any particular unit.

represent inches but a number that represents the ratio of 4 inches to 4

inches. The Reynolds number is a dimensionless quantity which can be

calculated using the following equation:

R

=

Reynolds number

Q

=

Flow rate in GPM

d

=

Inside diameter of pipe, in inches

K

=

Kinematic viscosity in centistokes (see Figure 1-1).

R = 3160 x Q

(where 3160 is a constant)

dxK

In this equation we use field data and we will concentrate on it in the

classroom. It is also the one used by the Army.

Reynolds number using design data.

V = Velocity in feet per sec

d = Inside diameter of pipe in ft

Y = Kinematic viscosity in feet squared (ft,,) per sec

R=Vxd

Y

able to use it. We know that the Reynolds number can tell you whether the

flow is laminar or turbulent. We can also determine a friction factor using

the Reynolds number. The friction factor relates to the resistance to flow

in pipeline operations. In our example using field data, we obtained a

Reynolds number of 144881. Because of the large number we will express it

in scientific notation. This is simply a way of expressing a number as a

decimal with one integer to the left of the decimal point times the

appropriate power of ten. For example: The number 144881 is expressed as

1.44x10 to the 5th power. In this case the decimal is moved 5 places to the

left 1.4x10 to the 5th power. The reverse is true for numbers less than

one, example: 0.00000064 becomes 6.4x10 to the (-) eighth. We just count 8

places to the right of the decimal.

following information:

Q = 350 gpm

D = 6.415 inches

Fuel = JP-4 at 50F

Figure 1-1 is a chart that gives you Kinematic viscosity for common military

fuels. Across the bottom of the chart from left to right is the temperature

in degrees Fahrenheit. On the left hand vertical side of the chart you will

find Kinematic viscosity in centistokes. First, locate 50 F on the bottom

12-10

QM 5099

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