Using Large Eddy Simulation to Study Airflows in and around Buildings

This investigation uses three subgrid-scale models of large eddy simulation (LES) to study airflows in and around buildings. They are the Smagorinsky model, a filtered dynamic subgridscale model and a stimulated small-scale subgrid-scale model. For outdoor airflow that is highly turbulent, the simple Smagorinsky model is sufficient. For indoor airflow where laminar flow can be as important as turbulent one, the filtered dynamic subgrid-scale model and the stimulated small-scale subgrid-scale model are recommended. However, the computing time required by the filtered dynamic subgrid-scale model and the stimulated small-scale subgrid-scale model are considerably higher than that by the Smagorinsky model. This paper also discusses how to set up boundary conditions for wind and how to simulate indoor and outdoor airflow together with good resolution and reasonable size of computational domain for natural ventilation studies.