Numerical simulation of reversed field pinches using a turbulence model

A numerical simulation of reversed field pinches is performed using a three-dimensional incompressible magnetohydrodynamic (MHD) code. A turbulence model called large eddy simulation is applied. Although field reversal is obtained in a simulation without the model, the skin current inconsistent with experiment is observed near the wall. The skin current vanishes and deeper field reversal is obtained by the use of the model. The balance of terms in the mean magnetic field equation is investigated to confirm the effect of the model. The magnetic energy and its spectrum are also presented to examine the character of magnetic fluctuations. (author)