Dynamic Pressure |
 
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Dynamic Pressure |
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Steady state internal fluid flow causes an increase in pipe wall tension (Fylling. et al., 1988) as follows:
(1)
where:
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is the change in pipe wall tension
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is the mass per unit length of the entrained fluid
•
is the velocity of the entrained fluid
In Flexcom, this effect is achieved by an increase in internal pressure, as follows:
(2)
where:
•ρ is fluid density
Note also that the instantaneous fluid density, ρ, can vary depending on whether the local element contains standard internal fluid or a passing slug. Moreover, the density of individual slugs may also vary over time.
•*INTERNAL FLUID is used to define the properties of an internal fluid. Dynamic pressure effects are included by default, but the DYNAMIC_PRESSURE= option allows you to suppress the effects of dynamic pressure in a particular analysis, allowing the relative significance of these loads to be assessed.