Date of Award

2003

Degree Name

M.S. in Chemical Engeneering

Department

Department of Chemical and Materials Engineering

Abstract

The addition of small concentrations of surfactant to an air/water two-phase flow through a 2 inch Schedule 40 (0.052 m-id) smooth PVC pipe resulted in significant changes to the flow pattern map and pressure loss of the system. Sodium dodecylsulfate was added to an air/water two-phase flow at several concentrations at or below the critical micelle concentration. As the surfactant concentration increased, the amount of foam generated in the flow increased, and several flow patterns not previously reported were observed. There was a reduction in the conditions under which intermittent flow patterns developed. It is proposed that the ability of the foam to dissipate local pressure gradients caused the reduction in the occurrence of intermittent flow. Pressure loss was measured for two-phase air/water stratified flow with and without surfactant. Addition of surfactant reduced the pressure loss in two-phase flow at concentrations that have no effect on single-phase, water only pressure loss. It is proposed that the liquid surface is less easily deformed in surfactant-containing flows due to surface concentration gradients created by interfacial forces, resulting in lower interfacial friction.

Keywords

Pipe Fluid dynamics, Two-phase flow, Surface active agents

Rights Statement

Copyright © 2003, author

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