Flow stability analysis of liquid first wall blanket with spiral channels for fusion reactor

The first wall material issue of fusion reactor blanket is one of the bottlenecks in the development of fusion energy. Due to the characteristics of liquidity and continuous renewing, the liquid first wall can withstand higher loads of thermal, neutron and temperature, with no limit in the service life. It's an attractive blanket design in the future application of fusion energy. In the existing designs of the liquid first wall, flow stability problem is still unsolved under the complex geometric structure with such severe operating conditions. One important aspect is flow instability caused by MHD (magneto hydrodynamics) effect. This paper presents a liquid first wall design utilizing spiral flow channels to reduce the MHD effect. Liquid metal flows in the spiral channels along the magnetic direction to avoid cutting the magnetic line. And the flow stability of this free surface liquid wall in a D shape gradient magnetic field is verified through VOF method. The analysis result shows a stable and integrated liquid first wall can be formed and the Lorentz force caused by magnetic field is very small compared to the driving force. (authors)