CFD Analysis of Turbulent Natural Ventilation in Double-Skin Facade: Thermal Mass and Energy Efficiency

摘要

Double-skin facade provides many opportunities for energy conservation in buildings. This work summarizes the results of a computational fluid dynamic (CFD) analysis, which was carried out to investigate the effect of blind and thermal mass concrete on the thermal performance of a double-skin facade. Navier-Stokes equations, turbulent k-s model, and discrete ordinates radiation model have been used to simulate the airflow and to study the airflow pattern. It was shown that the airflow patterns for natural ventilation with a blind and thermal mass concrete were very complex with multiple vortex structures. On the other hand, the heat flux and the airflow velocity at the inlet have a significant impact on the natural ventilation airflow rate. The Rayleigh number for turbulent flow was in the range of 10~7 s≤Ra≤ 10~8 using a blind. However, the Rayleigh number was less than 10~7 using thermal mass concrete. On the other hand, thermal mass increases the energy performance of natural ventilation. A good agreement was performed by comparing the experimental data and the simulation results.