Pressure Loss, Heat Transfer Coefficient and Flow Pattern in Drag-Reducing Two-Phase Flow of Air and Surfactant Solution Inside a Vertical Tube

Abstract

Surfactant additives can greatly reduce the friction factors of a heat transfer medium flowing in a tube. This was because the generation or growth of turbulent vortices is suppressed by rod-like micelles in a surfactant solution. However, since they decrease the heat transfer coefficient, we investigated the heat transfer enhancement by gas-liquid two-phase flow, and the flow and heat transfer characteristics in gas-surfactant solution two-phase flows. Injecting air significantly enhanced the heat transfer coefficients because it destroyed rod-like micelles or caused surfactant additives to accumulate at the gas-liquid interface, decreasing the apparent micelle concentrations.