Presentation Information
[3C04]Development of Validation Technology for Detailed Two-Phase Flow Simulation Codes to Optimize Innovative Reactor Design(10) Effect of Pipe Diameter on Liquid Film Behavior in Vertical Upward Annular Flow of an HFC134a Gas–Ethanol System
*Huacheng Zhang1, Yutaro Umehara1, Shoji Mori1, Naoki Horiguchi2, Hiroyuki Yoshida2 (1. Kyushu Univ., 2. JAEA)
Keywords:
Two-phase flow,Annular flow,Boiling water reactor,Liquid film
Accurate prediction of liquid film behavior in annular two-phase flow is essential for validating advanced simulation codes for innovative reactor design. However, direct measurements under BWR steam–water conditions are highly challenging. This study employs an HFC134a gas–ethanol system that reproduces key physical properties of steam–water annular flow at lower temperature and pressure. Experiments were conducted in vertical upward annular flow using pipes of various inner diameters to clarify diameter effects on film behavior. The constant electric current method enabled quantification of base, average, and maximum film thicknesses as well as disturbance-wave characteristics. The resulting database provides benchmark data crucial for validating next-generation detailed two-phase flow simulation codes.