Projekte von Dr. Matthias Sühring
Model-based city planning and application in climate change (MOSAIK-2)
Omar El Guernaoui, Dr. Sebastian Hettrich, Simone Pfau, Tobias Gronemeier, Dr. Ion Matei, Dr. Christopher Mount, Johannes Schwenkel, Dr. Matthias Sühring
The central goal of MOSAIK-2 within the 2nd phase of Urban Climate Under Change ([UC]2) is the further development of PALM-4U as a tool for practical applications by local authorities as well as for scientific applications.
Analysis of the relative importance of terrain heterogeneity, heterogeneous land use and heterogeneous forcing on the ABL structure using LES
The atmospheric boundary layer (ABL) is directly affected by the underlying surface. Inhomogeneous meteorological surface forcing can yield to circulations affecting the turbulent exchange in the entire ABL. This research project studies the effect of heterogeneous meteorological forcing on the structure of the ABL using LES. Simulations based on the LITFASS-2003 dataset will be carried out to investigate exchange processes and the state of turbulent mixing under different atmospheric conditions. Furthermore, the measurement strategies of the LITFASS-2003 experiment will be investigated and possible improvements for the measurement strategies will be derived.
Masterarbeiten / Diplomarbeiten
Development of a higher order advection scheme and its implementation in PALM
The numerical solution of the advection equation holds qualitatively strong dependencies on the wavenumber. Even scales in the range of the grid length show large errors in amplitude and phase speed. Furthermore, lower order discretization of the advection term implicates non-physical oscillations at strong gradients. So Stevens at al. (1999) assume that the resolved entrainment flux at the top of the boundary layer depend on the quality of the advection scheme. The 5th order finite difference scheme of Wicker and Skamarock (2002) possesses a well trade-off between numerical properties and computational costs. This thesis deals with the development of a higher order finite difference scheme based on the scheme of Wicker and Skamarock (2002) and its implementation in PALM. Also an optimization for large numbers of processors shall be accompanied. Furthermore, simulations of the convective boundary layer are carried out to show the enhanced numerical properties of this higher order advection scheme.