Reduced order models for Lagrangian hydrodynamics

Softened Lagrangian Hydrodynamics for Cosmology

A new approach to cosmological hydrodynamics is discussed which is based on a moving, quasi-Lagrangian mesh. The softened Lagrangian hydrodynamics (SLH) method utilizes a high resolution Lagrangian hydrodynamic code combined with a low resolution Eulerian solver to deal with severe mesh distortions. Most of the volume of a simulation is treated with the Lagrangian code and only in sites where t...

Staggered Grid Rd Scheme for Lagrangian Hydrodynamics

Abstract. This paper is focused on the Residual Distribution (RD) interpretation of the Do4 brev et al. scheme [Dobrev et al., SISC, 2012] for the numerical solution of the Euler equations 5 in Lagrangian form. The first ingredient of the original scheme is the staggered grid formulation 6 which uses continuous node-based finite element approximations for the kinematic variables and cell7 cente...

Parametric Reduced-Order Models

We address the problem of propagating input uncertainties through a computational fluid dynamics model. Methods such as Monte Carlo simulation can require many thousands (or more) of computational fluid dynamics solves, rendering them prohibitively expensive for practical applications. This expense can be overcome with reduced-order models that preserve the essential flow dynamics. The specific...

On Incompressible Averaged Lagrangian Hydrodynamics

Reduced-Order Subscales for POD models

In this work the Reduced-Order Subscales for Proper Orthogonal Decomposition models are presented. The basic idea consists in splitting the full-order solution into the part which can be captured by the reduced-order model and the part which cannot, the subscales, for which a model is required. The proposed model for the subscales is defined as a linear function of the solution of the reduced-o...