【摘要】 用热膜探针对内径为 35mm的水平管内泡状流中的紊流结构进行了测量 ,发现在管道下部非常低的局部含气率处 ,紊流脉动速度和紊流强度与单相液流时的相应值类似 ,而在管道上部的高含气率处 ,气泡的出现极大地增强了脉动速度和紊流强度 ,局部的紊流强度是局部含气率的强函数 .靠近管中心稍偏上的区域在一定的参数范围内 ,相应于较高气流折算速度的紊流脉动和紊流强度低于低气流折算速度的相应值 .紊流强度的分布规律从铅垂方向到水平方向随测量角度的增大而趋于对称 .更多还原

【Abstract】 Liquid 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 hot film 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.更多还原