[2H15-18] Multiphase Flow2

4:05 PM - 4:20 PM JST(7:05 AM - 7:20 AM UTC)

[2H15] Effective diffusion coefficient in wall condensation from steam-air mixture

*Michio Murase¹, Toshiya Takaki¹ (1. Institute of Nuclear Safety System, Inc.)

Keywords:

Wall condensation,Non-condensable gas,Heat flux,Diffusion coefficient,Boundary condition

The subjects of this study were a correlation for condensation heat flux q_c and a wall function for steam mass fraction Y_s, which are used as boundary conditions on structure surfaces in computational fluid dynamics (CFD) analysis for thermal hydraulic behavior in a containment vessel (CV) during accident conditions. We obtained the effective diffusion coefficient D_eff in the turbulent region from a logarithmic function of Y_s, and evaluated a prediction method for q_c on a vertical flat plate from steam and air mixture by using D_eff. This method simplified computing q_c.