ThermoFluidCalc Engineering Report

Two-Phase Gas-Liquid Flow Analysis โ€” 2026-09-26 22:24:41
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๐ŸŒ€ Two-Phase Gas-Liquid Pipe Flow

Solve two-phase pressure drops using Friedel & Lockhart-Martinelli correlations, Rouhani-Axelsson void fraction, and identify flow regimes.

โšก Fortran 90 Engine Double Precision (IEEE 754) โœ“ ISO / ASME Validated
Two-Phase Gas-Liquid Pipe Flow Fluid Mechanics
๐Ÿ“Š Solver Telemetry โ— ACTIVE
๐Ÿ‘๏ธ Views 28
โšก Solves 24
๐Ÿ’พ Downloads 487 ๐Ÿ“ฆ Fortran Code 4.5 KB
๐Ÿ“… Released Jun 2026
โฑ๏ธ Latency < 1 ms
โšก TOOLS & REPORTS:
๐Ÿ’พ Download Fortran 90
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๐ŸŒ€ Two-Phase Gas-Liquid Flow Regime Simulation

Real-time dynamic visualization of phase distribution & interfaces

๐Ÿ“ Configuration & Presets

โ™จ๏ธ Steam-Water Boiler (Vertical) ๐Ÿ›ข๏ธ Oil-Gas Pipeline (Slug) โ„๏ธ R134a Evaporator Tube ๐Ÿ’จ Air-Water Transport
๐Ÿ“ Pipe Geometry & Orientation
0ยฐ = horizontal, 90ยฐ = vertical upward
โšก Flow Conditions & Quality
๐Ÿ’ง Liquid Phase Properties
๐Ÿ’จ Gas / Vapor Phase Properties
Key Formulations:
โ€ข Friedel Multiplier: (dP/dz)2ฯ† = ฮฆL0ยฒ (dP/dz)L0
โ€ข Lockhart-Martinelli: Xtt = [(1โˆ’x)/x]0.9 (ฯG/ฯL)0.5 (ฮผL/ฮผG)0.1
โ€ข Void Fraction: ฮฑ = Drift Flux (Rouhani-Axelsson)
โ€ข Total ฮ”P = ฮ”Pfric + ฯ2ฯ† g L sin(ฮธ)

๐Ÿ“Š Simulation Results

๐Ÿ“Š Output Summary
๐Ÿ’พ Fortran Source

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 (ฮ”Ptot) 35.31 kPa 0.353 bar
Void Fraction (ฮฑ) 93.5% Liquid Holdup HL = 6.5%
Frictional Multiplier (ฮฆL0ยฒ) 36.12x ฮ”Pfric = 35.31 kPa
In-situ Mixture Density (ฯ2ฯ†) 98.6 kg/mยณ ฮ”Pgrav = 0.00 kPa

๐Ÿ“ˆ Friedel Two-Phase Multiplier ฮฆL0ยฒ vs Quality x

๐Ÿ“‰ Void Fraction ฮฑ vs Vapor Quality x

=================================================================
 THERMOFLUIDCALC โ€” TWO-PHASE GAS-LIQUID PIPE FLOW REPORT
=================================================================
Case Title                 : R134a Refrigeration Evaporator Tube
Pipe Diameter (D)          : 12.00 mm (1.2000e-2 m)
Pipe Length (L)            : 6.00 m
Inclination Angle (theta)  : 0.00 deg
Total Mass Flow Rate       : 0.050 kg/s
Total Mass Flux (G)        : 442.10 kg/(m2.s)
Vapor Quality (x)          : 0.5500
-----------------------------------------------------------------
Superficial Liquid Vel (jL): 0.159 m/s
Superficial Gas Vel (jG)   : 13.509 m/s
Lockhart-Martinelli (Xtt)  : 0.1340
Friedel Multiplier (Phi2)  : 36.1223
-----------------------------------------------------------------
Void Fraction (alpha)      : 0.9346 (93.46 %)
Liquid Holdup (HL)         : 0.0654 (6.54 %)
In-situ Two-Phase Density  : 98.61 kg/m3
Predicted Flow Regime      : Annular-Mist Flow
-----------------------------------------------------------------
Frictional Pressure Drop   : 35.307 kPa (3.5307e+4 Pa)
Hydrostatic Pressure Drop  : 0.000 kPa (0.0000e+0 Pa)
TOTAL TWO-PHASE DELTA-P    : 35.307 kPa (3.5307e+4 Pa)
=================================================================

๐Ÿ“˜ 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 / ฯG) / [Cโ‚€ (x/ฯG + (1โˆ’x)/ฯL) + 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.