Lockhart–Martinelli parameter

The Lockhart–Martinelli parameter ($\chi$) 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:

$\chi =\frac{m_{\ell }}{m_g}\sqrt{\frac{{\rho }_g}{{\rho }_{\ell }}},$

where

• $m_{\ell }$ is the liquid phase mass flowrate;
• $m_g$ is the gas phase mass flowrate;
• ${\rho }_g$ is the gas density;
• ${\rho }_{\ell }$ is the liquid density.

See also

• Wet gas