Yang Jian1,Zhang Mingyuan2,Li Rongxian1,Hou Hongning2,Su Yuliang2
(1.Research Institute of Tsinghua University in Shenzhen,Shenzhen 518057,China;2.School of Energy and Power Engineering,Xi'an Jiaotong University,Xi'an 710049,China)
Abstract:An experimental study of the velocity distribution in the entry region of a horizontal air-water bubbly flow was presented, where hot-film anemometry technique was applied to the measurements of local liquid velocities and void fractions, and the superficial liquid velocities were taken as 3.5~4.0 m/s,and the superficial air velocities as 0~0.44 m/s.The experimental result indicates that the liquid velocity near the region increases with the increasing superficial one, and distributes more asymmetrically,The local void fraction increases with accelerated gas flow and the distribution tends more symmetrical.In the experimental region, where the ratio of the length to diameter L/D is larger than 109, the liquid velocity and void fraction profiles doesn't obviously vary with L/D, which means that a fully developed state is achieved．
Keywords:bubbly flow;developing length;liquid velocity;void fraction