Use this window to specify Pressure Drop Method for Open Pipe.
Pressure Drop Correlation
Select the appropriate Pressure Drop Correlation from the list.
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Pressure Drop Correlation |
Significance
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Beggs-Brill-Moody (default) |
This is the default correlation and it is recommended for most systems, especially single-phase systems.
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Olimens |
This correlation is used for gas condensate systems, which use the Eaton correlation to calculate liquid holdup, and Moody diagrams for friction factor.
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Dukler-Eaton-Flanigan |
This hybrid correlation is for gas condensate systems that are mainly gas.
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Gray |
Recommended for vertical gas condensate systems. It should not be used for horizontal lines.
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Hagedorn-Brown |
This method is recommended for vertical pipelines, and should not be used for horizontal pipes.
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Mukherjee-Brill |
Used for gas condensate systems. This method must be used with care due to its discontinuities. Use at least 2 pipe segments to avoid failures due to changing flow regimes.
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Beggs-Brill-Moody-Palmer |
This method uses the same correlations as above and also includes the Palmer modification to account for liquid holdup, based on experimental data for uphill and downhill lines.
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Convergence Tolerance
Supplies a relative convergence tolerance value for the calculated pressure drop per reactor segment, between successive iteration. By default, PRO/II uses one percent tolerance.
Flow Efficiency
This parameter is used for linear adjustment of the calculated pressure drop to match actual conditions. For given flow conditions, decreasing this value causes an increase in the calculated pressure drop. The value may be greater than 100 percent. It is recommended that data for roughness or Moody friction factor be provided for accurate calibration of results.
Moody Friction Factor
PRO/II usually calculates the friction factor from reactor roughness and Reynolds number using the modified Colebrook-White equations. You can supply a value for this field, if desired.
Roughness
A roughness value can be supplied either in Absolute or Relative units. By default, PRO/II supplies an absolute roughness of 0.0018 inch.
Acceleration Term
Check this option to include the acceleration pressure gradient. Under certain high velocity or high-pressure conditions, the Beggs and Brill acceleration term becomes unrealistically large and dominates the equation. Ignoring the term often results in a better answer in these cases.