SNS: A Solution-based Nonlinear Subspace method for time-dependent nonlinear model order reduction
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Several reduced order models have been successfully developed for nonlinear dynamical systems. To achieve a considerable speedup, a hyper-reduction step is needed to reduce the computational complexity due to nonlinear terms. Many hyper-reduction techniques require the construction of nonlinear term basis, which introduces a computationally expensive offline phase. A novel way of constructing nonlinear term basis within the hyper-reduction process is introduced. In contrast to the traditional hyper-reduction techniques where the collection of nonlinear term snapshots is required, the SNS method completely avoids the use of the nonlinear term snapshots. Instead, it uses the solution snapshots that are used for building a solution basis. Furthermore, it avoids an extra data compression of nonlinear term snapshots. As a result, the SNS method provides a more efficient offline strategy than the traditional model order reduction techniques, such as the DEIM, GNAT, and ST-GNAT methods. Numerical results support that the accuracy of the solution from the SNS method is comparable to the traditional methods.
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