Page 200 - Standard Handbook Of Petroleum & Natural Gas Engineering

Strength of Materials 185

A = n( = 1.767 in.'

Assuming C = 1 and applying Equation 2-66 gives

Q = (864)(1)(1.767)

= 3214 scfm

From Figure 2-20 the viscosity of the gas is
= 0.0106 cp
and from Equation 2-70

(28.8)( 3,2 14) (0.65)
R, = = 2.84 x lo6
(0.0106)(2)
From Figure 2-24, using p = 0.75, the value of the discharge coefficient is read as
c = 1.2. Now a new estimate of Q can be found as
(3
Q= - 3214=3,857scfm

Because further increases in the flowrate (see Figure 2-24) will produce no increase
in the discharge coefficient, it is unnecessary to do any further iterations.
For further information on this subject refer to Reference 1 and References 6-9.
STRENGTH OF MATERIALS

The principles of strength of materials are applied to the design of structures to
assure that the elements of the structures will operate reliably under a known set of
loads. Thus the field encompasses both the calculation of the strength and deformation
of members and the measurement of the mechanical properties of engineer-
ing materials.
Stress and Strain
Consider a bar of length L and uniform cross-sectional area A to which an axial,
uniformly distributed load with a magnitude, P, is applied at each end (Figure 2-25).
Then within the bar there is said to be uniaxial stress c, defined as the load, or force
per unit area

P
(3=- (2-71)
A
If the load acts to elongate the bar, the stress is said to be tensile (+), and if the load
acts to compress the bar, the stress is said to be compressive (-). For all real materials,