🌀 Two-Phase Gas-Liquid Pipe Flow

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

⚡ Fortran 90 Engine Double Precision (IEEE 754) ✓ ISO / ASME Validated

📊 Solver Telemetry ● ACTIVE

👁️ Consultations 28

⚡ Calculs faits 24

💾 Téléchargements 390 📦 Code Fortran 8.1 KB

📅 Mise en service Jun 2026

⏱️ Latence < 1 ms

🌀 Two-Phase Gas-Liquid Flow Regime Simulation

Real-time dynamic visualization of phase distribution & interfaces

📝 Configuration & Presets

♨️ Steam-Water Boiler (Vertical) 🛢️ Oil-Gas Pipeline (Slug) ❄️ R134a Evaporator Tube 💨 Air-Water Transport

📐 Pipe Geometry & Orientation

Pipe Diameter D [mm]:

Pipe Length L [m]:

Pipe Roughness ε [mm]:

Inclination Angle θ [°]: 0° = horizontal, 90° = vertical upward

⚡ Flow Conditions & Quality

Total Mass Flow ṁ [kg/s]:

Vapor/Gas Quality x [0–1]:

💧 Liquid Phase Properties

Liquid Density ρ_L [kg/m³]:

Liquid Viscosity μ_L [Pa·s]:

Interfacial Surface Tension σ [N/m]:

💨 Gas / Vapor Phase Properties

Gas Density ρ_G [kg/m³]:

Gas Viscosity μ_G [Pa·s]:

Key Formulations:
• Friedel Multiplier: (dP/dz)_2φ = Φ_L0² (dP/dz)_L0
• Lockhart-Martinelli: X_tt = [(1−x)/x]^0.9 (ρ_G/ρ_L)^0.5 (μ_L/μ_G)^0.1
• Void Fraction: α = Drift Flux (Rouhani-Axelsson)
• Total ΔP = ΔP_fric + ρ_2φ g L sin(θ)

📊 Simulation Results

📊 Output Summary
💾 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 (ΔP_tot) 127.87 kPa 1.279 bar

Void Fraction (α) 84.7% Liquid Holdup H_L = 15.3%

Frictional Multiplier (Φ_L0²) 12.27x ΔP_fric = 101.07 kPa

In-situ Mixture Density (ρ_2φ) 136.6 kg/m³ ΔP_grav = 26.80 kPa

📈 Friedel Two-Phase Multiplier Φ_L0² vs Quality x

📉 Void Fraction α vs Vapor Quality x

=================================================================
 THERMOFLUIDCALC — TWO-PHASE GAS-LIQUID PIPE FLOW REPORT
=================================================================
Case Title                 : Steam-Water Boiler Riser Tube (Vertical Upflow)
Pipe Diameter (D)          : 50.00 mm (5.0000e-2 m)
Pipe Length (L)            : 20.00 m
Inclination Angle (theta)  : 90.00 deg
Total Mass Flow Rate       : 2.500 kg/s
Total Mass Flux (G)        : 1273.24 kg/(m2.s)
Vapor Quality (x)          : 0.2500
-----------------------------------------------------------------
Superficial Liquid Vel (jL): 1.224 m/s
Superficial Gas Vel (jG)   : 15.915 m/s
Lockhart-Martinelli (Xtt)  : 0.5158
Friedel Multiplier (Phi2)  : 12.2735
-----------------------------------------------------------------
Void Fraction (alpha)      : 0.8465 (84.65 %)
Liquid Holdup (HL)         : 0.1535 (15.35 %)
In-situ Two-Phase Density  : 136.63 kg/m3
Predicted Flow Regime      : Annular-Mist Flow
-----------------------------------------------------------------
Frictional Pressure Drop   : 101.070 kPa (1.0107e+5 Pa)
Hydrostatic Pressure Drop  : 26.797 kPa (2.6797e+4 Pa)
TOTAL TWO-PHASE DELTA-P    : 127.867 kPa (1.2787e+5 Pa)
=================================================================

📘 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:

                    ΦL0² = E + 3.24 · F · H / (FrH0.045 · 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:

                    α = (x / ρG) / [C₀ (x/ρG + (1−x)/ρL) + 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.

ThermoFluidCalc Engineering Report