Hendrik Fischer

Leibniz Universität Hannover · Institute of Applied Mathematics

In this work, we apply reduced-order modeling to the parametrized, time-dependent, incompressible, laminar Navier-Stokes equations. The major goal is to reduce the computational costs by replacing the high-fidelity system by a low-rank approximation, which preserves the solution behavior. We utilize projection-based reduced basis methods and carry...

In this work, the dual-weighted residual (DWR) method is applied to obtain a certified incremental proper orthogonal decomposition (POD) based reduced order model. A novel approach called MORe DWR (Model Order Rduction with Dual-Weighted Residual error estimates) is being introduced. It marries tensor-product space-time reduced-order modeling with...

The paper presents a strategy to construct an incremental Singular Value Decomposition (SVD) for time-evolving, spatially 3D discrete data sets. A low memory access procedure for reducing and deploying the snapshot data is presented. Considered examples refer to Computational Fluid Dynamic (CFD) results extracted from unsteady flow simulations, whi...

The nonlinear Schrödinger equation plays an important role in wave theory, nonlinear optics and Bose‐Einstein condensation. Depending on the background, different analytical solutions have been obtained. One of these solutions is the soliton solution. In the real ocean sea, interactions of different water waves can be observed at the surface. There...

Although extreme or freak waves are repeatedly measured in the oceans, their origin is largely unknown. The interaction of different water waves is seen as one reason for their emergence. One way to consider nonlinear waves in deep water is to look at solutions of the nonlinear Schr\"odinger equation, which plays an important role in the determinat...