Numerical investigation on heat transfer and hydrodynamic characteristics of gas-liquid Taylor flow in capillaries
ZHOU Nai xiang, ZHANG Jing zhi, LIN Jin pin, LI Wei
1. Shandong Urban and Rural Planning and Design Institute, Jinan 250013, China;
2. College of Energy Engineering, Zhejiang University, Hangzhou 310027, China
Numerical work of fully developed gas-liquid Taylor flow in vertical upward capillaries with inner diameter of 1 mm under isothermal wall boundary condition was performed with the dynamic mesh model. The effects of inlet Reynolds number and gas void fraction on thermal and flow characteristics of Taylor flow were discussed. Results indicate that the friction factor in the liquid slug is higher than that of single-phase flow, and the empirical correlation can predict the numerical data well. The apparent liquid slug Nusselt number increasing with increasing gas void fraction and remains nearly constant with increasing inlet Reynolds number. The Taylor bubble and the thin liquid film region have insignificant contribution to the overall heat transfer coefficients in Taylor flow under isothermal wall boundary condition. The inner recirculation in the liquid slug region can improve the heat transfer between the tube wall and the core region, accelerate the heat transfer process, and enhance the heat transfer performance in Taylor flow. The effect of inner recirculation on heat transfer enhancement decreases with increasing liquid slug length．
ZHOU Nai xiang, ZHANG Jing zhi, LIN Jin pin, LI Wei. Numerical investigation on heat transfer and hydrodynamic characteristics of gas-liquid Taylor flow in capillaries. JOURNAL OF ZHEJIANG UNIVERSITY (ENGINEERING SCIENCE), 2016, 50(10): 1859-1864.
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