Radial distribution and formation mechanism of thevoid fraction in an inclined circular tube
-
摘要: 采用光纤探针测量方法,对倾斜圆管中气液两相流动的空泡径向分布特性进行了实验研究,并对其形成原因进行了分析.实验选用有机玻璃圆管内径为50mm,竖直倾斜角度为5°,15°和30°,液相折算速度为0.071~0.284m/s,气相折算速度的范围为0~0.05m/s.结果表明:随着倾斜角度的增加,空泡份额径向分布逐渐由“核峰”、“壁峰”分布向单一“壁峰”分布转变;通过分析气泡受到的横向升力、浮力径向分量和壁面力,发现升力、浮力、壁面力的共同作用,使气泡在圆管径向位置15mm与22mm之间处聚集,从而造成空泡份额沿径向呈“壁峰”型分布.Abstract: Void fraction radial distribution of gas-liquid two phase flow in an inclined circular tube was investigated experimentally by using an optical fiber probe, and the reason for its formation was also illustrated. Experiments were conducted in an inclined circular tube made of perspex with inner diameter of 50 mm, and inclination angles of 5°, 15° and 30°. The specific liquid velocity was 0.071~0.284m/s and the specific gas velocity covered the range of 0~0.5m/s. The results show that, with increase of the inclined angle, the radial distribution of void fraction gradually shifts from the ‘core peak’ and ‘wall peak’ to the single ‘wall peak’ distribution. The analysis of the buoyancy component in radius and lateral lift forces as well as wall force acting on bubbles shows that the combined effects of these forces lead to the bubbles gathering around the radial position between 15 mm and 22 mm, resulting in the ‘wall peak’ distribution of the void fraction.
-
Key words:
- two-phase flow /
- fiber probe /
- void fraction /
- lift force /
- wall force
-
[1] 陈学俊,陈立勋,周芳德.气液两相流与传热基础[M].北京:科学出版社,1995. [2] 于勇,刘淑艳,张世军,等.固体火箭发动机喷管气固两相流动的数值模拟[J]. 航空动力学报,2009,24(5):931-937. YU Yong,LIU Shuyan,ZHANG Shijun,et al.Numerical simulation of gas-particle flow in nozzle of solid rocket motor[J].Journal of Aerospace Power,2009,24(5):931-937.(in Chinese) [3] 王延忠,牛文韬,唐文,等.航空直齿轮喷油润滑油气两相流分析[J].航空动力学报,2013,28(2):439-444. WANG Yanzhong,NIU Wentao,TANG Wen,et al.Reserch on oil-air multiphase flow of spray lubrication of aero spur gears[J].Journal of Aerospace Power,2013,28(2):931-937.(in Chinese) [4] Hibiki T,Ishii M.One-dimensional drift-flux model and constitutive equations for relative motion between phases in various two-phase flow regimes[J].International Journal of Heat and Mass Transfer,2003,46(25):4935-4948. [5] 田道贵,孙立成,刘靖宇,等.较大管径中两相流动漂移流模型研究[J].原子能科学技术,2013,47(2):229-232. TIAN Daogui,SUN Licheng,LIU Jingyu,et al.Study on drift-flux model for two-phase flow in relative large diameter channel[J].Atomic Energy Science and Technology,2013,47(2):229-232.(in Chinese) [6] 幸奠川,孙立成,阎昌琪,等.倾斜圆管内泡状流空泡份额特性实验研究[J].核动力工程,2012,33(4):111-115. XING Dianchuan,SUN Licheng,YAN Changqi,et al.Experimental investigation on characteristics of void fraction for bubbly flow in an inclined circular tube[J].Nuclear Power Engineering,2012,33(4):111-115.(in Chinese) [7] 田道贵,孙立成,高菲,等.光学探针在气液两相流动局部参数测量中的应用研究[J].实验流体力学,2012,26(6):91-95. TIAN Daogui,SUN Licheng,GAO Fei,et al.A study on application of optical probes for the measurement of local parameters in two-phase flow[J].Journal of Experiments in Fluid Mechanics,2012,26(6):91-95.(in Chinese) [8] Drew D,Lahey D.The virtual mass and lift force on a sphere in rotating and straining inviscid flow[J].International Journal of Multiphase Flow,1987,13(1):113-121. [9] Tomiyama A,Tamai H,Zun I.Transverse migration of single bubbles in simple shear flows[J].Chemical Engineering Science,2002,57(10):1849-1858. [10] Marco P D,Grassi W,Memoli G.Experimental study on rising velocity of nitrogen bubble in FC-72[J].Inernational Journal of Thermal Sciences,2003,42(5):435-466. [11] Hibiki H,Ishii M.Lift force in bubbly flow systems[J].Chemical Engineering Science,2007,62(7):6457-6474. [12] Chuag M S,Lee S J,Chang K S.Effect of interfacial pressure jump and virtual mass terms on sound wave propagation in the two-phase flow[J].Journal of Sound and Vibration,2001,244(4):717-728. [13] Krepper E,Reddy Vanga B N,Zaruba A,et al.Experimental and numerical studies of void fraction distribution in rectangular bubble columns[J].Nuclear and Design,2007,237(4):399-408. [14] Ishii M,Zuber N.Drag coefficient and relative velocity in bubbly,droplet or particulate flows[J].AICHE Journal,1979,25(5):843-855. [15] Lucas D,Kreppera E,Prasser H M.Use of models for lift,wall and turbulent dispersion forces acting on bubbles for poly-disperse flows[J].Chemical Engineering Science,2007,62(15):4146-4157. [16] Lahey R T,Jr.,Bertodano M L,Jones O C,Jr.Phase distribution in complex geometry conduits[J].Nuclear Engineering and Design,2001,141(1/2):177-201.
点击查看大图
计量
- 文章访问数: 1408
- HTML浏览量: 0
- PDF量: 1015
- 被引次数: 0