An experimental and numerical study of the smoke ventilation in atrium fires under dynamic ventilation performance

Abstract

Paper presented to the 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Florida, 14-16 July 2014.Smoke control systems within fire safety designs are being commonly investigated by means of computation fluid dynamics (CFD) models due to the increment of accuracy and computational speed. This paper presents a full-scale experimental and numerical comparison of atrium fires of 2.3- 2.7 MW and 5.1-5.3 MW using Fire Dynamic Simulator (FDSv6). Results from six different fire tests with dynamic and constant exhaust flow rates during the fire are presented. Different mesh element sizes as well as turbulence models (Deardorff, Dynamic Smagorinsky and Smagorinsky models) assessing the smoke layer interface are compared presentingdifferences in the steady state of 20% and 10%, respectively. A good agreement is obtained numerically, being the average relative error during the whole experiment of 12% and 17% in low and high heat release rates, respectively. Finally, the smoke layer has been well predicted not only under constant flow rates but also under dynamic flow rates, being the numerical temporal response to the exhaust changes conducted slower than the experimental one.