Flow patterns and heat transfer in vertical upward air-water flow with surfactant

Flow patterns, the pressure drag reduction and the heat transfer in a vertical upward air-water flow with the surfactant having negligible environmental impact were studied experimentally in a tube of 2.5 cm in diameter. Visual observations showed that gas bubbles in the air-water solution with surfactant are smaller in size but much larger in number than in pure air-water mixture, at the all flow regimes. The transition lines in the flow regime map for the solution of air-water mixture with surfactant of the 300 ppm concentration are mainly consistent with the experimental data obtained in clear air-water mixture. An additive of surfactant to two-phase flow reduces the total pressure drop and decrease heat transfer, especially in the chum flow regime. (c) 2006 Elsevier Ltd. All rights reserved.