Turbulence Structure in Horizontal Air-Water Bubbly Flow
Yang Jian¹£¬Zhang Mingyuan¹£¬Zhang Chaojie¹£¬Su Yuliang¹£¬Ren Changchun²
(1£®School of Energy and Power Engineering,Xi'an¡¡Jiaotong¡¡University,Xi'an 710049,China£»2£®Package College,Jilin University)

Abstract£ºLiquid phase turbulence sturcture of air-water bubbly flows in a horizontal tube with an inside diameter £¨ID£© of 35 mm is measured with a thermal system instrument £¨TSI£© cylindrical hotª²film probe. It is found that the turbulent intensity and turbulent velocity fluctuation are about the same as that of single liquid phase flow at the lower parts of the tube where the void fraction is extremely low or zero. In the upper part of the tube the introduction of air strongly enhanced the turbulence level as characterized by the turbulent velocity fluctuation and turbulent intensity with their maximum value near the upper wall of the tube. In general, the local turbulent intensity is a strong function of the local void fraction. However, in the region near to or a bit higher than the center of the tube and in a certain range of water and air flow rates, lower turbulent level at high air flow rate is measured than that at low air flow rate. Asymmetric profile of turbulence intensity is eventurally reached when measuring direction is changed from vertical and inclined to horizontal ones.
Keywords£ºair-water bubbly flow£»hot-film probe£»turbulent intensuity