Two-Phase Pressure Drop

Estimate gas-liquid pipe pressure drop with a Lockhart-Martinelli multiplier and a visual phase split.

visual calculatorMultiphase Flow

Read the flow shape before trusting the number.

This page turns a CFD setup into regime, scale, and dominant-effect cues. Adjust the calculator below and compare the moving graphic with the computed result.

input scale

model

check

two-phase flowLockhart-Martinellipressure dropvoid fraction

formula

KaTeX rendered

\begin{aligned}\text{phi\_l\^{}2 = 1 + C/X + 1/X\^{}2}\\[0.35em]\text{(dp/dz)\_tp = phi\_l\^{}2 (dp/dz)\_l}\end{aligned}

ASCII source

phi_l^2 = 1 + C/X + 1/X^2, (dp/dz)_tp = phi_l^2 (dp/dz)_l

quality xmass flux G (kg/m2/s)pipe D (m)pipe L (m)rho_l (kg/m3)rho_g (kg/m3)mu_l (Pa s)mu_g (Pa s)LM C

X_LM

0.4763

phi_l^2

47.399

dp/dz 2phi (Pa/m)

4920.35

Delta p total (Pa)

2.460e+4

Re_l / Re_g

1.111e+4 / 8.929e+4

Fast screening model only. Use detailed flow-pattern correlations before final sizing or safety decisions.

two-phase flow Lockhart-Martinelli pressure drop void fraction