Asymptotic Generalizations of the Lockhart–Martinelli Method for Two Phase Flows

The Lockhart–Martinelli (1949, “Proposed Correlation of Data for Isothermal Two Phase Flow, Two Component Flow in Pipes,” Chem. Eng. Prog., 45, pp. 39–48) method for predicting two phase flow pressure drop is examined from the point of view of asymptotic modeling. Comparisons are made with the Lockhart–Martinelli method, the Chisholm (1967, “A Theoretical Basis for the Lockhart-Martinelli Correlation for Two Phase Flow,” Int. J. Heat Mass Transfer, 10, pp. 1767–1778) method, and the Turner–Wallis (1969, One Dimensional Two Phase Flow, McGraw-Hill, New York) method. An alternative approach for predicting two phase flow pressure drop is developed using superposition of three pressure gradients: single phase liquid, single phase gas, and interfacial pressure drop. This new approach allows for the interfacial pressure drop to be easily modeled for each type of flow regime such as bubbly, mist, churn, plug, stratified, and annular, or based on the classical laminar-laminar, turbulent-turbulent, laminar-turbulent, and turbulent-laminar flow regimes proposed by Lockhart and Martinelli.