Analysis of Air-Water Two-Phase Flow in a 3x3 Rod Bundle

Authors: Pei-Syuan Ruan, Ya-Chi Yu, Shao-Wen Chen, Jin-Der Lee, Jong-Rong Wang, Chunkuan Shih

Abstract:

This study investigated the void fraction characteristics under low superficial gas velocity (J_g) and low superficial fluid velocity (J_f) conditions in a 3x3 rod bundle geometry. Three arrangements of conductivity probes were set to measure the void fraction at various cross-sectional regions, including rod-gap, sub-channel and rod-wall regions. The experimental tests were performed under the flow conditions of J_g = 0-0.236 m/s and J_f = 0-0.142 m/s, and the time-averaged void fractions were recorded at each flow condition. It was observed that while the superficial gas velocity increases, the small bubbles started to cluster together and become big bubbles. As the superficial fluid velocity increases, the local void fractions of the three test regions will get closer and the bubble distribution will be more uniform across the cross section.

Keywords: Conductivity probes, rod bundles, two-phase flow, void fraction.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.3669202

References:

[1] K. Mishima and M. Ishii, “Flow regime transition criteria for upward two-phase flow in vertical tubes,” International Journal of Heat and Mass Transfer, vol. 27, May 1984, pp. 723-737.
[2] M. Ishii and T. Hibiki, Thermo-Fluid Dynamics of Two-Phase Flow. New York, Springer, 2006.
[3] S.W. Chen, Y. Liu, T. Hibiki, M. Ishii, Y. Yoshida, I. Kinoshita, M. Murase, K. Mishima, “One-dimensional drift-flux model for two-phase flow in pool rod bundle systems,” International Journal of Multiphase Flow, vol.40, pp. 166-177, Apr. 2012.
[4] S.W. Chen, Y. Liu, T. Hibiki, M. Ishii, Y. Yoshida, I. Kinoshita, M. Murase, K. Mishima, “Experimental study of air–water two-phase flow in an 8 × 8 rod bundle under pool condition for one-dimensional drift-flux analysis,” International Journal of Heat and Fluid Flow, vol.33, pp. 168-181, Feb. 2012.
[5] S.W. Chen, M.S. Lin, F.J. Kuo, M.L. Chai, S.Y. Liu, J.D. Lee, B.S. Pei, "Experimental Investigation and Identification of the Transition Boundary of Churn and Annular Flows using Multi-Range Differential Pressure and Conductivity Signals", Applied Thermal Engineering, vol. 114, pp. 1275–1286, Sep. 2016.