Multiphase Flow Correlations

NeqSim provides several empirical and mechanistic correlations for multiphase pipe flow. This page covers the three main correlations, when to use each, and code examples.

Correlation Comparison

Correlation Class Inclination Best For
Beggs & Brill (1973) PipeBeggsAndBrills All angles General-purpose, most-used industry default
Hagedorn-Brown (1965) PipeHagedornBrown Vertical / near-vertical Oil production wells, gas lift wells
Mukherjee-Brill (1985) PipeMukherjeeAndBrill All angles Improved holdup prediction, flow pattern map

Selection Guidelines

Hagedorn-Brown Correlation

The Hagedorn-Brown (1965) method is an empirical holdup correlation developed for vertical wells. It does not predict flow patterns but uses dimensionless correlations to estimate liquid holdup as a function of flow rates, fluid properties, and pipe geometry.

Pressure Gradient

The total pressure gradient combines hydrostatic, friction, and acceleration terms:

\[\frac{dP}{dL} = \frac{\rho_m g \sin\theta}{1 - \frac{\rho_m v_m v_{sg}}{P}} + \frac{f \rho_m v_m^2}{2 d}\]

where $\rho_m$ is the mixture density based on the Hagedorn-Brown holdup, $v_m$ is the mixture velocity, $v_{sg}$ is the superficial gas velocity, and $f$ is the Moody friction factor.

Usage

import neqsim.process.equipment.pipeline.PipeHagedornBrown;

PipeHagedornBrown well = new PipeHagedornBrown("Production Tubing", feedStream);
well.setLength(3000.0);     // 3000 m TVD
well.setDiameter(0.1);      // 4-inch tubing
well.setElevation(-3000.0);  // Vertical downward (production)
well.setNumberOfIncrements(50);
well.setPipeWallRoughness(4.5e-5);
well.run();

// Results
double outletPressure = well.getOutletStream().getPressure();
double[] pressureProfile = well.getPressureProfile();
double[] temperatureProfile = well.getTemperatureProfile();
double liquidHoldup = well.getLiquidHoldup();

System.out.println("Outlet P: " + outletPressure + " bara");
System.out.println("Liquid holdup: " + liquidHoldup);

Mukherjee-Brill Correlation

The Mukherjee-Brill (1985) correlation extends the Beggs-Brill approach with improved holdup predictions for all pipe inclinations and an updated flow pattern map.

Flow Patterns

The correlation identifies five flow patterns based on dimensionless parameters:

Flow Pattern FlowPattern Enum Description
Stratified STRATIFIED Low flow — gas on top, liquid on bottom
Slug SLUG Intermittent liquid slugs
Annular ANNULAR Gas core with liquid film on wall
Bubble BUBBLE Dispersed gas bubbles in liquid
Single phase SINGLE_PHASE Only gas or only liquid

Usage

import neqsim.process.equipment.pipeline.PipeMukherjeeAndBrill;

PipeMukherjeeAndBrill pipeline = new PipeMukherjeeAndBrill("Export Pipeline", feedStream);
pipeline.setLength(25000.0);   // 25 km
pipeline.setDiameter(0.254);   // 10-inch
pipeline.setElevation(0.0);    // Horizontal
pipeline.setNumberOfIncrements(100);
pipeline.setPipeWallRoughness(4.5e-5);
pipeline.run();

// Results
double outletP = pipeline.getOutletStream().getPressure();
String pattern = pipeline.getFlowPattern();
double liquidHoldup = pipeline.getLiquidHoldup();
List<String> patternProfile = pipeline.getFlowPatternProfile();

System.out.println("Outlet P: " + outletP + " bara");
System.out.println("Outlet flow pattern: " + pattern);

Downhill Flow

Mukherjee-Brill handles downhill flow (negative inclination) better than Beggs-Brill, making it suitable for terrain-following pipelines:

pipeline.setElevation(-200.0);  // 200 m downhill over pipeline length
pipeline.run();

Beggs & Brill (Existing)

The Beggs & Brill (1973) correlation is NeqSim’s most established multiphase pipe flow model. See the dedicated documentation:

Comparing Correlations

To compare pressure drop predictions from different correlations on the same conditions, create three pipe instances with the same inlet stream:

// Feed stream
Stream feed = new Stream("Feed", fluid);
feed.setFlowRate(50000.0, "kg/hr");
feed.run();

// Beggs & Brill
PipeBeggsAndBrills pBB = new PipeBeggsAndBrills("BB", feed);
pBB.setLength(5000.0);
pBB.setDiameter(0.2);
pBB.setElevation(-5000.0);  // Vertical downward
pBB.setNumberOfIncrements(50);
pBB.run();

// Hagedorn-Brown
PipeHagedornBrown pHB = new PipeHagedornBrown("HB", feed);
pHB.setLength(5000.0);
pHB.setDiameter(0.2);
pHB.setElevation(-5000.0);  // Vertical downward
pHB.setNumberOfIncrements(50);
pHB.run();

// Mukherjee-Brill
PipeMukherjeeAndBrill pMB = new PipeMukherjeeAndBrill("MB", feed);
pMB.setLength(5000.0);
pMB.setDiameter(0.2);
pMB.setElevation(-5000.0);  // Vertical downward
pMB.setNumberOfIncrements(50);
pMB.run();

System.out.printf("Beggs-Brill outlet P: %.1f bara%n", pBB.getOutletStream().getPressure());
System.out.printf("Hagedorn-Brown outlet P: %.1f bara%n", pHB.getOutletStream().getPressure());
System.out.printf("Mukherjee-Brill outlet P: %.1f bara%n", pMB.getOutletStream().getPressure());

Profile Data Extraction

All three correlations return profile data as double[] arrays (one value per increment) for integration with plotting tools:

Method Returns Available On
getPressureProfile() double[] All three
getTemperatureProfile() double[] All three
getLiquidHoldup() double HagedornBrown, MukherjeeAndBrill
getFlowPatternProfile() List<String> MukherjeeAndBrill only
getFlowPattern() String MukherjeeAndBrill
getFlowPatternEnum() FlowPattern MukherjeeAndBrill