MULTIGRID METHODS FOR MORTAR-TYPE ROTATED Q_1 ELEMENT
MORTAR型旋转Q_1元的多重网格方法

In this paper,multigrid algorithms for mortar-type rotated Q_1 element are proposed.It is proven that the W-cycle multigrid method is optimal,i.e.,the convergence rate is inde- pendent of the mesh size and mesh level.Meanwhile a variable V-cycle multigrid algorithm is presented,which provides a preconditioner with a uniformly bounded condition number. Finally,numerical experiments are given to confirm our theoretical results.