The Empirical Equation of Interfacial Area Concentration Under Steady Fully-Developed Forced Convective Bubbly Flow
N Fuangworawong, W. Wangjiraniran, H. Kikura, M. Aritomi and T. Yamauchi
An interfacial phenomenon has been a topic of interest in the study of two-phase flow dynamics. In this paper, an empirical equation of interfacial area concentration under steady fully-developed flow condition in bubbly flow is formulated. This study applies Wire Mesh Tomography (WMT) to obtain experimental database of upward vertical air-water flow in a round pipe with an inner diameter of 50 mm. The accuracy of interfacial area concentration is presented by a comparison between WMT and a non-invasive optical method. The averaged deviation between them is less than 20 %. The accuracy of void fraction and Sauter mean diameter are also verified in this study. The 303 experimental data sets covering the superficial liquid velocity of 50 – 5,000 mm/s, the superficial gas velocity of 1.0-487 mm/s, the void fraction of 0.57 – 32.7%, the Sauter mean diameter of 1.7-10 mm and the interfacial area concentration of 8.91-551 m-1 are employed for developing the empirical equation. This empirical equation is a function of several parameters, with Sauter mean diameter up to 10 mm. The maximum bubble size in previous data sets has been limited to 5 mm. Finally, the empirical equation is compared against experiment data sets by various investigators. The averaged deviation is less than 10 %.