Computational study of natural ventilation in a sustainable building with complex geometry

Abstract

We deploy a fully coupled thermo-fluidic finite element approach to simulating natural ventilation in a sustainably designed building with complex geometry. The ‘interlock house’ uses building design for climate control instead of mechanical means (such as air conditioning). Therefore, accurately modeling the natural ventilation flows is crucial to assess thermal comfort in such designs. A residual-based variational multiscale method (VMS) is employed, which is a Large Eddy Simulation (LES) type approach to turbulence modeling. The VMS formulation is further augmented with a weakly enforced boundary condition method to efficiently resolve the effect of boundary layers. We validate the framework using a canonical Rayleigh Bénard convection problem across different flow regimes. We deploy the framework to analyze thermal flows in the house under two natural ventilation configurations characterized by window opening strategies. Mesh convergence study using one of the configurations is performed to verify the framework. Comparisons of the flow fields and temperature distributions between the two scenarios are discussed. Air diffusion performance index (ADPI) and predicted mean vote (PMV) are computed to investigate thermal comfort in both configurations. This work illustrates the ability of the framework to comprehensively model and predict natural ventilation under various operating scenarios.