D. I. Mendělěěv as reflected in his friendship to Professor Bohuslav Brauner

Two‐phase flow patterns in large diameter vertical pipes

“…The experimental results indicate a gradual shift from agitated bubbly to churn flow. The trends predicted by Taitel et al, [30] McQuillan and Whalley [32] and Brauner and Barnea [33] are all in contradiction to the experimental trends. It is to be noted that the transition curves in Taitel et al [30] and McQuillan and Whalley [32] terminate at slug to bubble transition boundary.…”

“…Although many researchers have not made any distinction in the above dispersed bubbly flow and this bubbly flow (also referred as non-dispersed bubble flow), [28,29] others have classified this flow as low-liquid-input bubbly flow or non-dispersed bubbly flow. [30][31][32][33][34] In this flow regime, the bubbles were of distorted spherical shapes in large population closely packed in the liquid phase. There was also some localized coalescing of the distorted bubbles in the core region forming larger distorted bubbles during upward flow upon increasing air superficial velocity.…”

“…The above flow patterns and the transitions in large diameter vertical upflow condition were compared with the theoretical predictions of some well-known flow pattern maps/models [29][30][31][32][33][34]37,38] derived from small diameter vertical upflow condition. For the sake of brevity, the related equations are not presented here and can be obtained from the original work of the researchers.…”

“…This observation is consistent with the experimental results of Omebere-Iyari et al [10] for pipe size of 189 mm and of Omebere-Iyari et al [11] for pipe size of 194 mm where similar trends as observed in this work were found for the Taitel et al [30] model. The experimental results and the performances of the slug to churn flow transition models [29,30,[32][33][34]38] are depicted in Figure 9. The experimental results indicate a gradual shift from agitated bubbly to churn flow.…”