Draft – to Be Submitted to Isfnt-5, Rome, September 1999 Novel Liquid Blanket Configurations and Their Hydrodynamic Analyses for Innovative Confinement Concepts

Hydrodynamics analyses as a part of APEX (Advanced Power Extraction) study shows the possibility of applying swirling thick liquid walls to innovative confinement concepts such as Field Reversed Configuration (FRC), Spherical Torus (ST) and Heavy-Ion Fusion (HIF). This paper addresses the design and the hydrodynamic aspects of fusion relevant swirling flow including 3-D velocity distribution, variations of the flow height in axial and azimuthal directions and hydrodynamic flow stability. Numerical hydrodynamic analyses using a 3-D code with Flibe as the working fluid shows that thick liquid first-wall / blanket (> 0.6 m) can be maintained in a circular vacuum chamber of 2 m radius by injecting the liquid layer at one side through a swirl flow generating inlet with axial (7 m/s) and azimuthal (10 m/s) velocity components. Parametric computational study indicated that the liquid layer thickness in axial and azimuthal directions is strongly dependent to inlet axial, azimuthal velocity values and gravitational acceleration, and a uniform liquid layer thickness can be maintained for axial and azimuthal inlet velocities of 11 m/s and 13 m/s in a cylindrical chamber with 2 m radius and 12 m length. Swirling liquid wall idea is applied successfully to ST and HIF configurations. 2-d linear stability analysis using potential flow theory (Reynolds number is ~10 for liquid wall thickness of ~ 0.5 m) of the swirling flow in azimuthal flow direction suggested that mean flow is stable when the surface tension, gravitational acceleration, the centrifugal acceleration effects are considered.