Simulations of filamentary structure in an edge‐localized mode burst on EAST using BOUT++ code

In this paper, simulation on the filamentary structure for the low‐hybrid wave heating H‐mode on experimental advanced superconducting tokamak (EAST) is carried out for the first time using BOUT++, and the speed and width of edge localized mode (ELM) filaments have been evaluated during the simulation. The evolutions of the ELM filaments are illustrated temporally and spatially. Then the results are compared with the experimental observations. It is found that at the peak gradient region in the outer midplane, the radial speed of the filaments is changed frequently and varied from 0.016 to 0.38 km/s. For the contrast, the poloidal speed oscillates in a narrower range of 0.68–0.88 km/s. The calculation results show the width of ELM filaments oscillates during the simulation, the minimum width is around 8.3 mm, and the maximum value is 41.24 mm. The distributions of the ELM filament widths with the radial position indicate the width is decreased with the radial position. Furthermore, by tracing one single filament, the radial width is decreased gradually when the filament is moving outward, which is also consistent with experiment conclusion. The consistencies also indicate the availability and practicability of the six‐field two‐fluid model of BOUT++ on the study of ELMs.