Numerical study of influence of J × B force on melt layer under conditions relevant to ITER ELMs**Project supported by the Scientific Research Foundation of Liaoning Province, China (Grant No. 2016J027), the Open Research Project of Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Ministry of Education (Grant No. KF1705), and the National Key Research and Development

Abstract

The influence of the J × B force on the topographical modification of W targets during a type-I-like ELM in ITER has been studied numerically. A two-dimensional (2D) fluid dynamics model is employed by solving liquid hydrodynamic Navier-Stokes equation with the 2D heat conduction equation in addition to driving forces for surface topography, such as surface tension and pressure gradient, the J × B force is particularly addressed. The governing equations are solved with the finite volume method by adequate prediction of the moving solid-liquid interface. Numerical simulations are carried out for a range of type-I ELM characteristic parameters. Our results indicate that both the surface tension and the J × B force contributes to the melt motion of tungsten plates when the energy flux is under , the surface tension is a major driving force while the pressure gradient is negligible. Our results also indicate that the J × B force makes the small hills grow at different rates at both the crater edges under a type-I-like ELM heat load with a Gaussian power density profile.