A simple method for identifying bubbling/jetting regimes transition from large submerged orifices using electrical capacitance tomography (ECT)

The bubbling–jetting transition regimes from large orifice submerged in water were investigated for various orifice diameters. A simple and fast way for identifying the regime transition was successfully developed using electrical capacitance tomography (ECT). In all the experiments deionised water was liquid phase and air was gas phase. Orifice gas velocity (VN) and orifice diameter (do) were varied from 0.8 to 186 m/s and 4–21 mm, respectively. It was found that the VN,trans. strongly depends on the orifice diameter. In the small orifice diameter (do 10 mm), the effect of orifice diameter on the transition velocity is insignificant. Finally, the data obtained by ECT compares with other works and the dimensionless orifice Reynolds number (Reo ∼11,000) is preferred to identify the bubbling–jetting transition regimes. On a étudié les régimes de transition barbotage‐giclement à partir de gros orifices submergés dans l'eau, et ce pour divers diamètres d'orifice. Un moyen simple et rapide d'identifier la transition de régime a été développé avec succès en utilisant la tomographie à capacitance électrique (ECT). Dans toutes les expériences, l'eau désionisée constituait la phase liquide et l'air la phase gazeuse. La vélocité gazeuse à l'orifice (VN) et le diamètre de l'orifice (do) variaient de 0,8 à 186 m/s et de 4 à 21 mm, respectivement. On a observé que la VN,trans dépendait fortement du diamètre de l'orifice. Pour les petits diamètres d'orifice (do