Numerical simulation of air-water two-phase flow in 38 mm diameter pipe by advanced two-fluid model including effects of turbulent diffusion on bubbles

気泡の乱流拡散を考慮した改良二流体モデルによる38mm管内空気-水二相流の数値解析

細井 秀章*; 吉田 啓之  

Hosoi, Hideaki*; Yoshida, Hiroyuki

In the Japan Atomic Energy Agency, an advanced two-fluid model has been developed for analytical procedure for nuclear reactor systems. In the model, an interface tracking method is combined with the two-fluid model to predict large interface structure behavior accurately. The turbulent dispersion force term is one of the most important constitutive equations for the advanced two-fluid model. Then, in this study, we proposed a new turbulent dispersion force term model based on the analogy of Brownian motion. The turbulent kinetic energy and bubble-induced kinetic energy are considered to evaluate the driving force in the turbulent diffusion of small bubbles. The advanced two-fluid model and the model for turbulent diffusion term were incorporated to the 3-dimensional two-fluid model code ACE-3D, and verification analyses were performed with the air-water two-phase flow experimental data in vertical pipes with diameters of 200 mm and 38 mm. From these results, the qualitative phenomena could be expressed and the model constants including suggested model were selected.