Axial interfacial area transport of vertical bubbly flows

Recently, the concept of the interfacial area transport equation has been p roposed to develop the constitutive relation on the interfacial area concen tration in relation to the modeling of the interfacial transfer terms in th e two-fluid model. Accurate data sets On axial development of local flow pa rameters such as void fraction. interfacial area concentration, interfacial and liquid velocities and turbulence intensity are indispensable to verify the modeled source and sink terms in the interfacial area transport equati on. From this point of view, local measurements of vertical upward air wate r flows in a round tube with an inner diameter of 50.8 mm were performed at three axial locations of z/D = 6.00, 30.3 and 53.5 as well as 15 radial lo cations from r/R = 0 0.95 by using the double-sensor probe and the hotfilm probe. In the experiment, the superficial liquid velocity and the void frac tion ranged from 0.491 to 5.00 m/s and from 4.90% to 44.2%. respectively. T he flow condition covered extensive region of bubbly flow's including finel y dispersed bubbly flow as well as bubbly-to-slug transition flow. The comb ined data from the double-sensor probe and the hotfilm probe give near comp lete information on the time averaged local hydrodynamic parameters of two- phase flow. This data can be used for the development of reliable constitut ive relations which reflect the true transfer mechanisms in two-phase flow. (C) 2001 Elsevier Science Ltd. All rights reserved.