Numerical simulation of the flow in Michel-Stadt II

Abstract

In this contribution the flow field in a complex, generic European city center is studied by means of computational fluid dynamics to prepare validation simulations of the dispersion of a continuously released passive scalar in this city center model, with the assessment of urban air pollution modeling in mind. The statistically steady flow field is computed for two wind directions with the commercial flow solver Ansys Fluent 14.5, using the standard k-" turbulence model. The results for one wind direction are compared to experimental data from a wind tunnel experiment by means of validation metrics. The current metrics are similar to corresponding data obtained in a slightly different geometry of the city model on different meshes and with different flow solvers. For the second wind direction no experimental data are available and the numerical results are compared to the ones of the validated wind direction, to illustrate and analyze the differences. All simulations are conducted on two unstructured, hexahedral meshes to investigate the sensitivity of the results to the mesh resolution.