Two-Phase Flow Calculator

Calculate flow regimes, void fraction, and pressure drop for gas-liquid systems

Flow Rates

Gas Flow Rate (kg/s)

Liquid Flow Rate (kg/s)

Pipe Geometry

Diameter (m)

Length (m)

Inclination (degrees)

0° = horizontal, +90° = vertical up, -90° = vertical down

Fluid Properties

Gas Density (kg/m³)

Liquid Density (kg/m³)

Gas Viscosity (Pa·s)

Liquid Viscosity (Pa·s)

Surface Tension (N/m)

Typical Values

Air: ρ=1.2 kg/m³, μ=1.8×10⁻⁵ Pa·s

Water: ρ=1000 kg/m³, μ=0.001 Pa·s

Water-Air: σ=0.072 N/m

Slug

Moderate velocities — intermittent liquid slugs

Void Fraction α

99.5%

Quality x

20.00%

Total ΔP

1,904.25kPa

Pressure Gradient

19.0425kPa/m

Superficial Velocities

Gas (V_sg)

5.3052m/s

Liquid (V_sl)

0.025465m/s

Mixture (V_m)

5.3306m/s

Pressure Drop Components

Frictional

1,904.25kPa

Gravitational

0.0000e+0kPa

Total

1,904.25kPa

Frictional Gravitational

Dimensionless Parameters

Re_liquid

2546

Re_gas

35368

Fr_liquid

0.001

Fr_gas

28.700

46.9

X_LM

0.193

Flow Regime Map (Taitel-Dukler Type)

_sg (m/s)Superficial Liquid Velocity V_sl (m/s)

Current flow: V_sg = 5.31 m/s, V_sl = 0.025 m/s

Void Fraction: 100% gas

Pressure Drop: High — check pipe sizing

About Two-Phase Flow

Two-phase flow involves the simultaneous flow of gas and liquid through a pipe. Understanding flow regimes is critical for predicting pressure drop, heat transfer, and system stability in oil & gas, refrigeration, and process industries. This calculator uses the homogeneous model for void fraction and the Lockhart-Martinelli method with the Chisholm correlation for frictional pressure drop.