An Adaptive Deflation Domain-Decomposition Preconditioner for Fast Frequency Sweeps

An adaptive multi-point model-order reduction is a well-established methodology for computing fast frequency sweeps of finite-element (FE) models. For structures that are electrically large, however, generating the reduced-order system is computationally expensive, because both the size of the FE model and the number of expansion points become large. Thus, a great number of independent large-scale systems of linear equations must be solved by iterative methods. To alleviate this problem, this paper proposes to employ the reduced-order system already available at a given adaptive step for constructing an efficient two-level preconditioner. Two numerical examples demonstrate the benefits of the suggested approach.