Void faction of bubbly flow in a subchannel geometry at an adiabatic condition

Air-water two-phase flow experiments were conducted on a 4x4 rod bundle array at an adiabatic condition. Bundle array was consisted of 16 rods with a diameter of 25.4 mm, a rod to rod pitch of 33.7 mm. A double-sensor optical probe with the automatic controlled traverse system was used for the measurement of flow parameters such as local void fraction, interfacial velocity, Sauter mean diameter and interfacial area concentration in a subchannel. Precise data sets were acquired consisting of superficial gas velocities, about 0.13, 0.26 and 0.53 m/s at a superficial liquid velocity, 1.60 m/s. The detailed profiles of two-phase flow parameters in a subchannel were obtained and the phase distribution patterns according to the bubble conditions were discussed