Smagorinsky constant in studying smoke exhaust in a big irregular hall with large eddy simulation

Large eddy simulation with the Smagorinsky subgrid-scale model is widely used for studying smoke movement and evaluating performance of smoke management systems in big construction sustainable projects in East Asia. However, there are not much validation studies on simulating smoke movement by those Computational Fluid Dynamics (CFD) fire models. Predicated results on smoke movement with and without operating the smoke management system depend on the Smagorinsky constant. Effect of varying the Smagorinsky constant on the predicted results is not clear and will be studied in this paper. Field tests on smoke exhaust in such a hall of length 40 m, width 11 m and height 28 m under a 2 MW methanol pool fire were taken as reference. Values of Smagorinsky constant were varied from 0.1 to 0.22 in simulating smoke exhaust in that big hall. Predicted smoke layer interface height by the CFD software Fire Dynamics Simulator with those values was justified. Results illustrated that varying the Smagorinsky constant in this range would not affect significantly the predicted smoke layer interface height. Using a value of 0.20 is reasonable in simulating smoke movement and control in big halls with irregular shapes commonly found in projects with sustainable green architectural features.