title: A Spectral Discontinuous Galerkin method for incompressible flow with Applications to turbulence creator: Piatkowski, Stephan-Marian subject: ddc-004 subject: 004 Data processing Computer science subject: ddc-500 subject: 500 Natural sciences and mathematics subject: ddc-510 subject: 510 Mathematics subject: ddc-530 subject: 530 Physics description: In this thesis we develop a numerical solution method for the instationary incompressible Navier-Stokes equations. The approach is based on projection methods for discretization in time and a higher order discontinuous Galerkin discretization in space. We propose an upwind scheme for the convective term that chooses the direction of flux across cell interfaces by the mean value of the velocity and has favorable properties in the context of DG. We present new variants of solenoidal projection operators in the Helmholtz decomposition which are indeed discrete projection operators. The discretization is accomplished on quadrilateral or hexahedral meshes where sum-factorization in tensor product finite elements can be exploited. Sum-factorization significantly reduces algorithmic complexity during assembling. In this thesis we thereby build efficient scalable matrix-free solvers and preconditioners to tackle the arising subproblems in the discretization. Conservation properties of the numerical method are demonstrated for both problems with exact solution and turbulent flows. Finally, the presented DG solver enables long time stable direct numerical simulations of the Navier-Stokes equations. As an application we perform computations on a model of the atmospheric boundary layer and demonstrate the existence of surface renewal. date: 2019 type: Dissertation type: info:eu-repo/semantics/doctoralThesis type: NonPeerReviewed format: application/pdf identifier: https://archiv.ub.uni-heidelberg.de/volltextserverhttps://archiv.ub.uni-heidelberg.de/volltextserver/26674/1/Piatkowski_Dissertation.pdf identifier: DOI:10.11588/heidok.00026674 identifier: urn:nbn:de:bsz:16-heidok-266746 identifier: Piatkowski, Stephan-Marian (2019) A Spectral Discontinuous Galerkin method for incompressible flow with Applications to turbulence. [Dissertation] relation: https://archiv.ub.uni-heidelberg.de/volltextserver/26674/ rights: info:eu-repo/semantics/openAccess rights: http://archiv.ub.uni-heidelberg.de/volltextserver/help/license_urhg.html language: eng