A validation of large eddy simulation for complex urban environments

The use of large eddy simulation is becoming an important assessment tool in the field of atmospheric transport and dispersion in urban environments. This paper describes a massively parallel building airflow model which will eventually be able to investigate scale interactions of more than two orders of magnitudes. These scale interactions range from those of the typical feature on a building 0(2) meters to a larger horizontal extent of multiple buildings and a vertical extent that may extend to the atmospheric boundary layer height. The model has an advanced finite element construction which allows complex geometrical configurations to be modeled. We briefly describe the object-oriented construction of the model and show how it can be used to study turbulent airflow over an isolated cubic block. This study illustrates the ability of large eddy simulation to capture transient dynamics which are important to concerns of complex urban environments. We conclude with plans to extend this study to arrays of rectangular blocks which are more representative of the complexity often found in urban environments.