CFD predictions of turbulent two-phase flow in helical coils

Turbulent two-phase flow in a helical pipe was simulated by means of CFD using the ANSYS-CFX code, based on a finite-volume multi-fluid approach. The focus was on flow patterns and frictional pressure drops; inter-phase heat and mass transfer and heat exchange with the pipe walls were not included and physical properties were assumed constant for each phase. The computational domain included a single, vertical axis, coil turn; the flow was assumed to be fully developed. Geometry and physical conditions were representative of the IRIS nuclear reactor steam generators (saturated water at 58 bar, pressure gradient of 0.1 bar/m). Void fraction and computational options (homogeneous vs. inhomo…