Thermal fluid multiphysics optimization of spherical tokamak centerpost

Highlights: ► The purpose of this study is to optimize the design of water cooling channels in an ST centerpost. ► The temperature in the centerpost can be substantially reduced by optimizing the channel design. ► The channels can be designed to maintain acceptable temperatures for a fully nuclear environment. - Abstract: An experimental Fusion Nuclear Science Facility (FNSF) is required that will create the environment that simultaneously achieves high energy neutrons and high ion fluence necessary in order to bridge the gaps from ITER to the realization of a fusion nuclear power plant. One concept for achieving this is a high duty cycle spherical torus. This study will focus on thermal modeling of the spherical torus centerpost using computational fluid dynamics to effectively model the thermal transfer of the cooling fluid to the centerpost. The design of the fluid channels is optimized in order to minimize the temperature in the centerpost. Results indicate the feasibility of water cooling for a long-pulse spherical torus FNSF.