Structure-Preserving Hyper-Reduction Methods for the Incompressible Navier-Stokes Equations

In this master thesis several novel DEIM formulations are proposed that enable the construction of non-linearly stable hyper-reduced order models (hROMs) of the incompressible Navier-Stokes equations. The hROMs have the same mass, momentum and energy conservation properties as the previously proposed ROM, but they do not suffer of prohibitively...

Goal-Oriented, Reduced-Order Modeling of the Incompressible Navier-Stokes Equations: Application to a 2D transitional boundary layer

Research into constructing reduced-order models (ROM) to reduce computational cost or to interpret complex datasets from numerical or experimental sources has steadily been gaining popularity over the past few years. Many methods currently exist to construct ROMs. The proper orthogonal decomposition (POD) is one of the most widely adopted...

A Validation Study for the Computation of Nonlinear Modal Frequency using a Hamiltonian Reduced Order Model

A common structural design verification is to conduct modal analysis and to ensure that the vibration modes of the structure do not get harmonically excited during operation. Since the modal frequencies are dependent on the mass and stiffness properties of the structure, they are an influencing factor in the design optimization. Modal...

Towards a data assimilation system for morphodynamic modeling

Currently, available models are not able to accurately predict the temporal evolution of coastal morphodynamic processes. The main reason for this, is that essential components governing this evolution are neither fully identified nor understood. Additionally, there is high uncertainty in some of the parameterizations and their input parameters....

A Koiter-Newton arclength method for buckling-sensitive structures

Thin-walled structures, when properly designed, possess a high strength-to-weight and stiffness-to-weight ratio, and therefore are used as the primary components in some weight critical structural applications, such as aerospace and marine engineering. These structures are prone to be limited in their load carrying capability by buckling, while...

Numerical Simulation of Bubble and Droplet Dynamics using Partitioned Solvers

Bubbles and droplets can be simulated as a problem involving Fluid-Structure Interaction (FSI). The interface between the liquid and the gas is then conceived as a zero thickness structure. The position of the interface is determined by the equilibrium between surface tension effects and the pressure jump across the interface. Most techniques...

Strong coupling of partitioned fluid-structure interaction problems with reduced order models

The paper describes a new and powerful technique to solve strongly coupled fluid-structure interaction (FSI) problems with partitioned solvers. In order to achieve strong coupling approximate Jacobians of the fluid and structural solvers have to be known. In the proposed method the response to applied displacement and pressure modes are used to...