Abstract:
A two-dimensional system of the Stokes type, in which the coefficient of the highest order derivatives is a small parameter $\varepsilon>0$, is considered, and a version of the multigrid method is developed to handle a finite-element scheme for the system, obtained by using biquadratic elements for the velocities, linear elements for the pressure and an approximatively-solenoidal basis. Approximatively-solenoidal interpolations are defined and used to design the coarse-grid bases. Numerical experiments demonstrate a high rate of convergence even for very small $\varepsilon$ values.