倾斜管内上升泡状流界面参数分布特性实验研究

Experimental Study on Characteristics of Interfacial Parameter Distribution for Upward Bubbly Flow in Inclined Tube

采用双头光纤探针对倾斜圆管内空气-水两相泡状流界面参数分布特性进行了实验研究,包括局部空泡份额、气泡通过频率、界面面积浓度及气泡当量直径径向分布特性。实验段内径为50mm,液相表观速度为0.144m/s,气相表观速度为0～0.054m/s。结果表明倾斜管内向上泡状流气泡明显向上壁面聚集。局部界面浓度、空泡份额及气泡通过频率径向分布相似。倾斜条件下局部界面参数分布下壁面附近峰值相对于竖直状态被削弱甚至消失,上壁面附近峰值被加强,中间区域从下壁面往上逐渐增大,且随倾斜角度的增加变化更加剧烈。气泡等价直径随径向位置、气相速度及倾斜角度的不同无明显变化,气泡聚合和破碎现象较少发生。通过气泡受力分析解释了倾斜对泡状流局部界面参数分布的影响机理。

Experimental study on characteristics of interracial parameter distribution for air-water bubbly flow in an inclined circular tube was performed by using the double sensor probe method. Parameters including radial distributions of local void faction, bubble passing frequency, interfacial area concentration and bubble equivalent diameter were measured using the probe. The inner diameter of test section is 50 mm, and the liquid superficial velocity is 0. 144 m/s, with the gas superficial velocity ranging from 0 to 0. 054 m/s. The results show that bubbles obviously move toward the upper wall and congregate. The local interfacial area concentration, bubble passing frequency and void fraction have similar radial distribution profiles. Different from the vertical condition,for a cross-sectional area of the test section, the peak value near the upper side increa- ses, while decreases or even disappears near the underside. The local parameter increa- ses as the radial positions change from lower to upper location, and the increased slope becomes larger as the inclination angles increase. The equivalent bubble diameter doesn＇t vary with radial position, superficial gas velocity and inclination angle, and bubble aggregation and breaking up nearly doesn＇t occur. The mechanism of effects of inclination on local parameter distribution for bubbly flow is explained by analyzing the transverse force governing the bubble motion.