Lockhart–Martinelli parameter

The Lockhart–Martinelli parameter ([math]\displaystyle{ \chi }[/math]) is a dimensionless number used in internal two-phase flow calculations. It expresses the liquid fraction of a flowing fluid. Its main application is in two-phase pressure drop and boiling/condensing heat transfer calculations. It is defined as:

[math]\displaystyle{ \chi = \frac{m_\ell}{m_g} \sqrt{\frac{\rho_g}{\rho_\ell}}, }[/math]

where

• [math]\displaystyle{ m_\ell }[/math] is the liquid phase mass flowrate;
• [math]\displaystyle{ m_g }[/math] is the gas phase mass flowrate;
• [math]\displaystyle{ \rho_g }[/math] is the gas density;
• [math]\displaystyle{ \rho_\ell }[/math] is the liquid density.

See also

• Wet gas