AXIAL DEVELOPMENT OF INTERFACIAL AREA AND VOID CONCENTRATION PROFILESMEASURED BY DOUBLE-SENSOR PROBE METHOD

Interfacial area concentration is an important parameter in modeling t he interfacial transfer terms in the two-fluid model. In this paper, t he local geometric and statistical characteristics of upward cocurrent dispersed bubbly flow in a pipe have been studied both at the entranc e (L/D = 8) and at a region far away from the entrance (L/D = 60). The test section was a 5.08 cm i.d. and 375 cm long Lucite pipe. Four Liq uid flow rates ranging from 0.1 to 1.0 m s(-1) were used in combinatio n with four different gas injection rates ranging from 0.02 to 0.1 m s (-1). A double-sensor probe was employed to measure the radial profile s of void fraction, interfacial area concentration, Sauter mean diamet er, bubble velocity and bubble frequency. The wall peak of the void fr action profile was established within a short distance from the entran ce. The flow characteristics changed very little from the entrance reg ion to the fully developed region except for the flow case of j(1) = 0 .1 m (s-1). The area averaged Bow quantities were also presented.