Abstract
Slug flow characteristics in helically coiled tubes were investigated in experiments. Pressure loss, slug velocity, and slug passing frequency were measured using pressure transducers and backlight imaging of dyed water under illumination. For a 20-mm-diameter tube, parametric dependencies on gas and liquid volume flow rates for total superficial velocities of up to 6 m/s with three different radii of curvature (R = 0.270 m, R = 0.375 m, and R = infinity/straight tube) were explored. The main experimental results obtained are (1) the bubbly flow regime shrinks because of centrifugal acceleration from the coiled geometry, (2) the liquid slug length remains unchanged regardless of changes in gas and liquid flow rates, and (3) the pipe friction factor decreases with slug passing frequency.
Acknowledgments
This study was supported by the JAEA for fundamental research for the FBR. Data analysis and discussions were undertaken in collaboration with Shinji Yoshikawa (Japan Nuclear Cycle Development Institute), Katsuhiko Kondo (Japan Nuclear Cycle Development Institute), Shinichi Toda (Kawasaki Plant Systems, Ltd), Toshio Sasaki (University of Fukui), and Taiji Tanaka (Hokkaido University).
Disclosure Statement
No potential conflict of interest was reported by the author(s).