Two-phase phase distribution in a vertical large diameter pipe

Bubbly-to-cap bubbly flow transition in a long-26m vertical large diameter pipe at low liquid flow rate

“…In Fig. 2, the transition line from bubbly to slug flow identified by Mishima and Ishii (1984) and the transition line from wall peak radial phase distribution to core peak radial phase distribution proposed by Shen et al (2005a) were superimposed. In comparison to the short vertical large diameter pipe, the pressures in the long vertical large diameter pipe will be much greater and the resultant superficial gas velocity changes along the flow will be more significant.…”

“…A review of the current literature has revealed that a few works such as Ohnuki and Akimoto (2000), Sun et al (2002), Shen et al (2002), Prasser et al (2005 and2007), Omebere-Iyari et al (2008) and Shawkat et al (2008) have been done regarding local flow characteristics in short vertical large diameter pipe. We also have performed local measurements at two or three axial positions for the two-phase flow in long vertical large diameter pipe by using four-sensor probe and hot-film anemometer in our previous studies (Shen et al, 2005a(Shen et al, , 2010(Shen et al, , 2011(Shen et al, , 2012a. The currently available knowledge on the two-phase flow characteristics in a vertical large diameter can be summarized as (1) large stable Taylor bubbles cannot be formed due to interfacial instability and the radial void fraction profiles are different from those in small pipes in the cap/slug flow regime, (2) relative velocities between large bubbles and liquid are greatly increased relative to them in small diameter pipes due to the formation of pipe-size large bubbles resulting from the reduced influence of the pipe wall, (3) superposition of the wall-shear-induced turbulence and the bubble-induced turbulence results in the violent local flow swirling, especially at lower liquid flow rates.…”

Development of Research on Interfacial Area Transport

“…Shen and coworkers 57) at Kyoto University carried out experimental research on the flow structure of a two-phase flow in a large-diameter pipe (200 mm). Using a doublesensor optical probe, they measured the radial distribution of bubble diameter (Sauter mean diameter, d sm ) at several positions from the inlet.…”

Numerical study of bubbly upflows in a vertical channel using the Euler–Lagrange two-way model

“…Many evidences show that the local void fraction profile and interaction of bubbles and liquid are tightly related to factors such as the pipe diameter, the bubble size and shape, the global void fraction, the liquid turbulence structure around the bubble, the interphase force, etc. Experimental results of the literature (Cheng et al, 1998;Yoneda et al, 2002;Shen et al, 2005) show that bubbles, in the pipe of diameter larger than 100 mm, tend to migrate toward the pipe centerline forming a core-peak void fraction distribution, whereas a wall-peak void fraction distribution occurs in the pipe of relatively small diameter. Researchers experimentally found that the void fraction profile is strongly dependent on the size of the bubbles (Herringe and Davis, 1976;Wang et al, 1987;Zun, 1988;Ohnuki and Akimoto, 2000;Shoukri et al, 2003;Prasser et al, 2005;Shen et al, 2005;Shawkat et al, 2007).…”