A CHEBYSHEV PSEUDOSPECTRAL MULTIDOMAIN METHOD FOR A BOUNDARY-LAYER PROBLEM

A multidomain pseudospectral method, which is based on Chebyshev polyn omials expansions, is presented to solve an initial-boundary value pro blem in incompressible MHD, the tearing instability, in which a bounda ry layer is spontaneously generated inside the spatial domain. The met hod is based on a property of Chebyshev pseudospectral expansions whic h accurately describe functions having strong gradients localized near one of the Chebyshev domain boundaries. A comparison with the results of a single-domain pseudospectral method is performed, showing that, in the considered case, the multidomain technique furnishes a higher a ccuracy keeping the truncation error to a lower level. Because of the steeper Chebyshev spectra lower aliasing errors are obtained during th e nonlinear stage of the instability. (C) 1996 Academic Press, Inc.