Numerical studies on natural ventilation flow in an enclosure with both buoyancy and wind effects

Computational Fluid Dynamics (CFD) is used to predict natural ventilation flows in an enclosure with upper and lower openings connected to the environment. The natural driving forces are wind combined with buoyancy. CFD simulations were carried out by varying the strengths of buoyancy under a constant assisting wind effect. Simulation results of the volume flow rates through the enclosure, the stratification level and temperature distribution were compared with the corresponding experimental measurements and analytical studies by Hunt & Kaye (2001) and [2]. With the application of the RNG k-epsilon turbulence model and the proper considerations on the fluid boundaries, the overall computed airflow patterns and the airflow rates through the space agreed well with Hunt & Kaye (2001) and Hunt & Linden (2001). The close qualitative and quantitative agreement gave confidence in CFD technique for modelling natural ventilation flows in simple geometry buildings