Gas Dynamics in the Central Cavity of the HYLIFE-II Reactor†

The HYLIFE-II ICE reactor uses molten salt, Flibe (Li₂BeF₄), as a liquid blanket material. After the microexplosion of the D-T capsule in the center of the chamber the emitted x rays ablate a thin layer of the liquid and generate a high temperature plasma. This paper uses a second order Godunov numerical method to solve for the gas dynamics of the ablated material in the central cavity. Because the initial ablation has very small characteristic length scale (about 10 microns), a time varying mesh spacing is adapted. The equation of state for Flibe vapor is used in the calculation along with the parameters for the HYLIFE-II design. The results reveal that the gas dynamic response is sensitive to the initial energy deposition in the liquid and that two- dimensional shock effects are very important in determining the pressure and density field in the central cavity. By neglecting radiation heat transfer, the current calculation results give a conservative estimation of the shock strength.