activity
20242026
collaborators

10 papers

math.NA2026

Pressure-robustness for the axisymmetric Stokes problem by velocity reconstruction

Philip L. Lederer, Christoph Lehrenfeld, Christian Merdon +1

This paper studies pressure-robustness for the axisymmetric Stokes problem. The transformation to cylindrical coordinates requires that the radially weighted velocity is divergence…

math.NA2026

Releasing the pressure: High-order surface flow discretizations via discrete Helmholtz-Hodge decompositions

Tim Brüers, Christoph Lehrenfeld, Tim van Beeck +1

We present a discrete Helmholtz--Hodge decomposition for H(div)-conforming Brezzi--Douglas--Marini (BDM) finite elements on triangulated surfaces of arbitrary topology. The diverge…

math.NA2026

Embedded Trefftz DG method for steady Navier-Stokes flow. Part I: Oseen linearization

Paul Stocker, Igor Voulis, Christoph Lehrenfeld +1

We develop an embedded Trefftz-DG method for the Oseen problem and prove a complete stability and quasi-optimality theory in standard DG norms. The key ingredient is a construction…

math.NA2026

Embedded Trefftz DG method for steady Navier-Stokes flow. Part II: Nonlinear problem

Paul Stocker, Igor Voulis, Christoph Lehrenfeld +1

We develop and analyze an embedded Trefftz-DG method for the steady incompressible Navier-Stokes equations, based on the reduced Oseen discretization from Part I. The main difficul…

math.NA2025

Streamfunction-vorticity formulation for incompressible viscid and inviscid flows on general surfaces

Tim Brüers, Christoph Lehrenfeld, Max Wardetzky

This paper presents a streamfunction-vorticity formulation for the Navier--Stokes and Euler equations on general surfaces. Notably, this includes non-simply connected surfaces, on…

math.NA2025

Embedded Trefftz DG framework for the analysis of discretizations with local-global decompositions

Philip L. Lederer, Christoph Lehrenfeld, Paul Stocker +1

This paper presents a framework for the analysis of discretization methods based on the decomposition into local and global problems. We apply the framework to provide a comprehens…