A twisted block tangential filtering decomposition preconditioner (Q1036314)

Summary: For a block-tridiagonal system of linear equations, a variant of tangential filtering preconditioners is proposed. The new variant is based on a twisted block factorization along with a certain filtering property. For practical usage, a class of composite preconditioners is tested, which are constructed by combining the twisted tangential filtering decomposition preconditioner with the classical ILU(0) preconditioner in a multiplicative way. The performance of the new preconditioners is compared with other classical preconditioners; the superiority and the weakness of the preconditioners are pointed out.