Project Details
SPP 1276: Multiple Scales in Fluid Mechanics and Meteorology
Subject Area
Thermal Engineering/Process Engineering
Geosciences
Mathematics
Physics
Geosciences
Mathematics
Physics
Term
from 2007 to 2016
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 25965762
The reliable simulation of local extremes, such as precipitating fronts with high flood risk (meteorology) or local extreme temperatures in combustion chambers (fluid mechanics), is both of high practical importance and one of the major challenges in these research fields: How can we, e.g., simulate the 10-50 km sized "eye" of a hurricane together with the storm's determining large-scale environment at high fidelity without exhausting the available computing resources? One approach to this challenge relies on spatio-temporal grid-size adaptation controlled by both the pertaining flow conditions and by the questions the simulation is meant to answer. If, e.g., we are interested in the actual size, position and strength of the "eye" of a hurricane, then grid sizes of about 1 km should be sufficient; if we intend to simulate individual updraughts inside such a storm, then mesh widths of 100 m are more appropriate; if some range of turbulent fluctuations is to be represented as well, the mesh size must be even smaller; etc., all the way down to the micrometer-sized droplets within a cloud.
How should one, on a time-dependent grid that dynamically adapts to the flow state and to the simulation's targeted question, account for the fact that any change of the spatio-temporal grid size will shift the boundary between those processes that can and those that cannot be resolved on the computational mesh? What kind of combination of (scale-dependent) mathematical models and adaptive numerical schemes is suited to satisfy the standards of meteorology and fluid dynamics with respect to the reliability of a simulation as well as the standards of mathematics as far as well-posedness of the overall mathematical problem is concerned?
These are the key questions, which researchers from meteorology, fluid dynamics and mathematics address in bi- and tri-disciplinary projects within the Priority Programme. The projects aim at providing simulation models in which scale-dependent descriptions of physical processes, their mathematical formulation and the adaptive discretisations used to translate them to computer-tractable problems interleave consistently. For the representation of processes not resolved on the computational mesh, deterministic continuum-type models are considered as well as discrete and stochastic closure schemes. Besides the development of fundamental concepts and their prototypical implementation, novel error estimators are being developed, which allow the separate estimation of numerical and modelling errors, and which provide the basis for the dynamical control of grid and model adaptation. The theoretical projects are complemented by judiciously chosen experimental investigations providing reference data for simulation validation.
How should one, on a time-dependent grid that dynamically adapts to the flow state and to the simulation's targeted question, account for the fact that any change of the spatio-temporal grid size will shift the boundary between those processes that can and those that cannot be resolved on the computational mesh? What kind of combination of (scale-dependent) mathematical models and adaptive numerical schemes is suited to satisfy the standards of meteorology and fluid dynamics with respect to the reliability of a simulation as well as the standards of mathematics as far as well-posedness of the overall mathematical problem is concerned?
These are the key questions, which researchers from meteorology, fluid dynamics and mathematics address in bi- and tri-disciplinary projects within the Priority Programme. The projects aim at providing simulation models in which scale-dependent descriptions of physical processes, their mathematical formulation and the adaptive discretisations used to translate them to computer-tractable problems interleave consistently. For the representation of processes not resolved on the computational mesh, deterministic continuum-type models are considered as well as discrete and stochastic closure schemes. Besides the development of fundamental concepts and their prototypical implementation, novel error estimators are being developed, which allow the separate estimation of numerical and modelling errors, and which provide the basis for the dynamical control of grid and model adaptation. The theoretical projects are complemented by judiciously chosen experimental investigations providing reference data for simulation validation.
DFG Programme
Priority Programmes
International Connection
Austria, Switzerland, United Kingdom, USA
Projects
- Analysis and numerical simulation of stratocumulus clouds (Applicants Mellado, Juan Pedro ; Schmidt, Heiko ; Stevens, Bjorn )
- Diskret-kontinuierliche Hybridmodelle auf der Basis der integralen Erhaltungsprinzipien (Applicants Horenko, Illia ; Klein, Rupert ; Munz, Claus-Dieter )
- Ein hybrides Frontverfolgungs-Verfahren für Stratocumulus-Wolken unter Berücksichtigung instationärer "Entrainment"-Prozesse (Applicant Schmidt, Heiko )
- Entwicklung eines Lagrangeschen Kerns für Klimamodelle (Applicants Grewe, Volker ; Reich, Sebastian ; Yserentant, Harry )
- Erzeugung zeitlich und räumlich hochaufgelöster Validierungsdaten für LES-Simulationen turbulenter Strömungs- und Transportphänomene (Applicant Leitl, Bernd )
- Goal oriented adaptivity for tropical cyclones (Applicants Heuveline, Vincent ; Jones, Sarah C. )
- Investigations of droplet growth and precipitation formation in clouds (Applicants Beheng, Klaus Dieter ; Etling, Dieter ; Schröder, Wolfgang )
- Large Eddy Simulation mit adaptiven bewegten Gittern zur Lösung meteorologischer Fragestellungen (Applicants Fröhlich, Jochen ; Lang, Jens )
- MetStröm Koordination (Applicant Klein, Rupert )
- Modeling of diffusive and double-diffusive flows in ocean and in stars (Applicants Losch, Ph.D., Martin ; Spruit, Hendrik C. )
- Modellierung und Approximation feuchter atmosphärischer Strömungen unter Berücksichtigung topographischer Effekte (Applicants Gaßmann, Almut ; Helzel, Christiane ; Knoth, Oswald ; Wensch, Jörg )
- Parallel, adaptive simulation of multiscale phenomena and transparent boundary conditions for atmospheric flows (Applicants Baldauf, Michael ; Kröner, Dietmar )
- Referenzexperiment für Untersuchungen der Dynamik und Koexistenz von großräumigen und kleinskaligen Strömungsstrukturen am Beispiel barokliner und Schwerewellen (Applicant Egbers, Christoph )
- Referenzexperimente im mehrphasigen Windkanal, numerische Simulationen und Validierung (Applicants John, Volker ; Thévenin, Dominique )
- Skalenübergreifende Modellierung der Populationsdynamik von Hydrometeoren mit Momentenverfahren (Applicants Polifke, Ph.D., Wolfgang ; Wacker, Ulrike )
- Space-Time Adjustable Regularizations for the Atmospheric Circulation model ICON, Code name: STAR (Space-Time Adjustible Regularizations) (Applicants Giorgetta, Marco A. ; Reich, Sebastian )
- The impact of turbulent entrainment and mixing on the fine-structure of cloud turbulence (Applicants Raasch, Siegfried ; Schumacher, Jörg ; Siebert, Holger )
- The turbulent interaction among scale-separated gravity waves and between gravity waves and synoptic-scale flow (Applicants Achatz, Ulrich ; Hickel, Stefan )
- Turbulente Austauschprozesse zwischen Waldflächen und der Atmosphäre (Applicants Bernhofer, Christian ; Maas, Hans-Gerd ; Stiller, Jörg )
- Turbulenzstruktur in der urbanen Rauigkeitsschicht: LES-Referenzstudien und Vergleiche mit Windkanal-, Skalenmodell- und Feldmessungen (Applicant Raasch, Siegfried )
- Wechselwirkung von kleinen und großen dynamischen Skalen in einem adaptiven numerischen Modell für atmosphärische Feuchtkonvektion (Applicants Behrens, Jörn ; Wirth, Volkmar )
- Zielfunktional-orientierte Aktivität und Reduktion von atmosphärischen Chemietransportmodellen (Applicants Braack, Malte ; Schlünzen, Katharina Heinke )
Spokesperson
Professor Dr.-Ing. Rupert Klein