The Lockhart–Martinelli parameter ( χ {\displaystyle \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 was first used by R. W. Lockhart and Raymond C. Martinelli in 1949. It is defined as:
χ = m ℓ m g ρ g ρ ℓ , {\displaystyle \chi ={\frac {m_{\ell }}{m_{g}}}{\sqrt {\frac {\rho _{g}}{\rho _{\ell }}}},}
where
m ℓ {\displaystyle m_{\ell }} is the liquid phase mass flowrate;
m g {\displaystyle m_{g}} is the gas phase mass flowrate;
ρ g {\displaystyle \rho _{g}} is the gas density;
ρ ℓ {\displaystyle \rho _{\ell }} is the liquid density.
See also Wet gas
References