Bubble characteristics of steam–water two-phase flow in a large-diameter pipe

• Published in: Experimental thermal and fluid science Vol. 26; no. 6; pp. 669 - 676
• Main Authors: Yoneda, Kimitoshi, Yasuo, Akira, Okawa, Tomio
• Format: Journal Article Conference Proceeding
• Language: English
• Published: New York, NY Elsevier Inc 01.08.2002; Elsevier Science
• Subjects: Bubble chord length; Exact sciences and technology; Flows in ducts, channels, nozzles, and conduits; Fluid dynamics; Frequency distribution; Fundamental areas of phenomenology (including applications); Gas velocity; Large-diameter pipe; Multiphase and particle-laden flows; Nonhomogeneous flows; Physics; Steam–water two-phase flow; Void fraction; Steam–water two-phase flow; Void fraction; Gas velocity; Frequency distribution; Large-diameter pipe; Bubble chord length; Phase velocity; Bubbles; Particle size; Pipe flow; Two-phase flow; Vertical pipe; Liquid vapor interface; Frequency; Experimental study
• ISSN: 0894-1777; 1879-2286
• DOI: 10.1016/S0894-1777(02)00177-2

Bubble characteristics of steam–water two-phase upward flow were observed in a vertical pipe 155 mm in inner diameter. Experiments were conducted under volumetric flux conditions of J G<0.25 m/s and J L<0.6 m/s, and three different inlet boundary conditions to investigate the developing state of the flow. The radial distributions of flow structure were obtained by horizontally traversing optical dual void probes through the pipe. The spectra of bubble chord length and gas velocity were also obtained to study the characteristics of bubbles in detail. The flow reached a quasi-developed state within relatively short height to diameter aspect ratio of about H/ D=4 compared to a small-diameter pipe flow. The PDF profiles of bubble chord length and gas velocity were able to approximate fairly well by model function using Gamma distribution and log-normal distribution, respectively.