๐ Two-Phase Gas-Liquid Pipe Flow
Solve two-phase pressure drops using Friedel & Lockhart-Martinelli correlations, Rouhani-Axelsson void fraction, and identify flow regimes.
โก Fortran 90 Engine
Double Precision (IEEE 754)
โ ISO / ASME Validated
Fluid Mechanics
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Released
Jun 2026
โฑ๏ธ Latency
< 1 ms
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๐ Two-Phase Gas-Liquid Flow Regime Simulation
Real-time dynamic visualization of phase distribution & interfaces๐ Configuration & Presets
โจ๏ธ Steam-Water Boiler (Vertical)
๐ข๏ธ Oil-Gas Pipeline (Slug)
โ๏ธ R134a Evaporator Tube
๐จ Air-Water Transport
Key Formulations:
โข Friedel Multiplier: (dP/dz)2ฯ = ฮฆL0ยฒ (dP/dz)L0
โข Lockhart-Martinelli: Xtt = [(1โx)/x]0.9 (ฯG/ฯL)0.5 (ฮผL/ฮผG)0.1
โข Void Fraction: ฮฑ = Drift Flux (Rouhani-Axelsson)
โข Total ฮP = ฮPfric + ฯ2ฯ g L sin(ฮธ)
โข Friedel Multiplier: (dP/dz)2ฯ = ฮฆL0ยฒ (dP/dz)L0
โข Lockhart-Martinelli: Xtt = [(1โx)/x]0.9 (ฯG/ฯL)0.5 (ฮผL/ฮผG)0.1
โข Void Fraction: ฮฑ = Drift Flux (Rouhani-Axelsson)
โข Total ฮP = ฮPfric + ฯ2ฯ g L sin(ฮธ)
๐ Simulation Results
๐ Output Summary
Identified Two-Phase Regime
Annular-Mist Flow
High-speed gas core in the center shearing a thin liquid film along the pipe perimeter.
Total Pressure Drop (ฮPtot)
234.26 kPa
2.343 bar
Void Fraction (ฮฑ)
86.7%
Liquid Holdup HL = 13.3%
Frictional Multiplier (ฮฆL0ยฒ)
28.70x
ฮPfric = 227.38 kPa
In-situ Mixture Density (ฯ2ฯ)
134.1 kg/mยณ
ฮPgrav = 6.87 kPa
๐ Friedel Two-Phase Multiplier ฮฆL0ยฒ vs Quality x
๐ Void Fraction ฮฑ vs Vapor Quality x
================================================================= THERMOFLUIDCALC โ TWO-PHASE GAS-LIQUID PIPE FLOW REPORT ================================================================= Case Title : Compressed Air-Water Two-Phase Transport Line Pipe Diameter (D) : 80.00 mm (8.0000e-2 m) Pipe Length (L) : 60.00 m Inclination Angle (theta) : 5.00 deg Total Mass Flow Rate : 5.000 kg/s Total Mass Flux (G) : 994.72 kg/(m2.s) Vapor Quality (x) : 0.0400 ----------------------------------------------------------------- Superficial Liquid Vel (jL): 0.957 m/s Superficial Gas Vel (jG) : 32.481 m/s Lockhart-Martinelli (Xtt) : 0.9141 Friedel Multiplier (Phi2) : 28.6981 ----------------------------------------------------------------- Void Fraction (alpha) : 0.8667 (86.67 %) Liquid Holdup (HL) : 0.1333 (13.33 %) In-situ Two-Phase Density : 134.06 kg/m3 Predicted Flow Regime : Annular-Mist Flow ----------------------------------------------------------------- Frictional Pressure Drop : 227.381 kPa (2.2738e+5 Pa) Hydrostatic Pressure Drop : 6.875 kPa (6.8749e+3 Pa) TOTAL TWO-PHASE DELTA-P : 234.256 kPa (2.3426e+5 Pa) =================================================================
๐ Calculation Methodology & Engineering Theory
Friedel Two-Phase Multiplier
The Friedel (1979) correlation is widely accepted across ASME and HEI standards for turbulent liquid-gas flows in vertical and horizontal lines:
ฮฆL0ยฒ = E + 3.24 ยท F ยท H / (FrH0.045 ยท WeL0.035)
Drift-Flux Void Fraction ($\alpha$)
Accounting for the slip velocity between light vapor and dense liquid using Rouhani & Axelsson's drift-flux model:
ฮฑ = (x / ฯG) / [Cโ (x/ฯG + (1โx)/ฯL) + ugj / G]
Key Engineering Assumptions
- Adiabatic or slowly evaporating pipe flow (steady equilibrium quality).
- Newtonian liquid and gas phase behavior.
- Pipe wall friction evaluated via Churchill friction factor for both phases.
- Acceleration pressure gradient neglected for uniform diameter lines.