Large Eddy Simulation of Natural and Mixed Convection Airflow Indoors with Two Simple Filtered Dynamic Subgrid Scale Models

Large eddy simulation (LES) with a dynamic subgrid-scale model (DSM) is a powerful tool to predict indoor airflow. Some DSM models need to average the model coefficient over a homogeneous direction or need to use an additional parameter. The others are too complicated. This study proposes a simple filtered dynamic subgrid scale model (FDSM) for indoor flow without a homogeneous direction. The predicted air velocity, air temperature and turbulence distributions agree reasonably well with the experimental data. The results show that the FDSM can be used to simulate indoor airflow. NOMENCLATURE Ar : Archimedes number C: Model coefficient (C=Cs) Cs: Smagorinsky model coefficient D: Room depth G(xi): Filter function g: Gravitational acceleration H: Room height L: Room width i p : Grid filtered pressure Pr: Molecular prandtl number PrSGS: Subgrid-scale prandtl number Ra: Rayleigh number T: Temperature