HYSYS Operations Guide

7-40 Pipe Segment
Regime Model
Stratified Lockhart-Martinelli
Wave Lockhart-Martinelli
Hagedorn & Brown
Hagedorn & Brown based their model 11 on experimental data on
upward flow of air / water and air / oil mixtures. The frictional
pressure drop is calculated using a friction factor derived from a
single phase Moody curve using a two phase Reynolds number
that reduces to the appropriate single phase Reynolds number
when the flow becomes single phase. For the void fraction
required to calculate the two phase Reynolds number and the
static pressure loss, Hagedorn & Brown developed a single curve
relating the void fraction to the same dimensionless parameters
proposed by Duns & Ros.
HTFS Models
The two HTFS models 12, 17 share a common method for
calculating the frictional pressure gradient and acceleration
pressure gradient while differing in the method used to calculate
static pressure gradient.
The frictional pressure gradient method is adapted from that of
Claxton et. al. (1972). The method first calculates the frictional
pressure drop for the gas and liquid phases assuming that they
are flowing alone in the pipe based on Fanning friction factors
for each phase that are again calculated by assuming the fluid is
flowing alone in the pipe. The frictional pressure drop is then
calculated from the formula:
where:
∆pF
∆pl
∆pF
= ∆pl
+ Cc ( ∆pl∆pg
) + ∆pg
= frictional pressure drop
= liquid phase pressure drop
(7.12)
7-40