Keywords: complex terrain, conformal mapping, coordinate transformation, flow modelling, mesh generation, non-, orthogonal systems, orthogonal systems, meteorological models, air pollution, environmental pollution, atmospheric dispersion models
Realistic approach to 2-D flow modelling for complex terrain
The capabilities of regional and mesoscale meteorological models make them attractive to use in air pollution studies. Especially, flow modelling and dispersion analysis in complex terrain plays an important role in the control of emissions into the atmosphere. In the numerical simulation of an atmospheric phenomenon, various coordinate systems are used to represent the terrain and the vertical structure of the atmosphere. In many studies, the terrain-following coordinate transformation is used, although some problems exist in the vicinity of sharp edges of the topography. In this study, the Schwarz-Christoffel (SC) transformation is proposed to obtain realistic results rather than the terrain-following coordinate system. It is known that conformal mapping with SC transformation can be considered as a coordinate generation as well as a boundary integral method. SC transformation generates orthogonal grids to decrease the computational time in the simulation, and removes the singularities in the vicinity of sharp edges of the topography. The proposed method is more realistic and accurate in the flow modelling.