Block ILU factorization preconditioners for a block-tridiagonal H-matrix

We propose new parallelizable block ILU (incomplete LU) factorization preco nditioners for a nonsymmetric block-tridiagonal H-matrix. Theoretical prope rties of these block ILU preconditioners are compared with those of block I LU preconditioners for the corresponding comparison matrix. Numerical resul ts of the BiCGSTAB using these block preconditioners are compared with thos e of the BiCGSTAB using a standard ILU factorization preconditioner to see the effectiveness of the block ILU preconditioners. Lastly, parallel comput ations of the block nu preconditioners are carried out and evaluated on the Gray C90. (C) 2000 Elsevier Science Inc. All rights reserved.