Paper Conference

Proceedings of SimBuild Conference 2012: 5th conference of IBPSA USA


Annual Coupled EnergyPlus and Computational Fluid Dynamics Simulation of Natural Ventilation

Rui Zhang, Khee Poh Lam, Shi-Chune Yao, Yongjie Zhang
IBM, T.J. Watson Research Center, Yorktown Heights, NY, 10598
Carnegie Mellon University, Pittsburgh, PA 15213, USA

Abstract: Can coupled Computational Fluid Dynamics (CFD) and Building Energy Simulation (BES) be used to conduct annual simulation? This paper tries to investigate the feasibility of annual coupled simulation of CFD and BES. Energy modeling approaches have continued to advance to cater for emerging new design concepts towards “greener” solutions that optimize energy consumption in buildings while maintaining thermal comfort as well as healthy environment. Various efforts have been made to improve the fidelity of the thermal simulation in buildings such as to couple CFD with lumped nodal BES model. Research has shown that the coupled simulation improves simulation accuracy. However, due to the nature of CFD simulation, coupled simulation usually takes much longer computation time. For example, the annual simulation of natural ventilation, which has relatively fewer incidences of CFD simulation runs, would take up to 46 days. In addressing the issue, a coupled lumped heat transfer model (EnergyPlus) and CFD model (Fluent) was implemented, and 8 days of simulation was conducted. Delaunay Triangulation based interpolation model was built from the 8 days’ results, which can be used to predict the airflow rates for openings for an annual simulation. It is shown that the interpolation model is able to predict 35% of the natural ventilation deployable time annually, when natural ventilation is appropriate in the Philadelphia climate context. The interpolation model reduces the simulation time by 90%.
Pages: 314 - 321