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Computational Thermal Sciences: An International Journal
ESCI SJR: 0.249 SNIP: 0.434 CiteScore™: 0.7

ISSN Druckformat: 1940-2503
ISSN Online: 1940-2554

Computational Thermal Sciences: An International Journal

DOI: 10.1615/ComputThermalScien.2015011933
pages 181-189

LAGRANGIAN BLOCK SIMULATION OF BUOYANCY AT TURBULENCE INTERFACES

Vincent H. Chu
Department of Civil Engineering and Applied Mechanics, McGill University, 817 Sherbrooke St. West, Montreal, Quebec H3A0C3, Canada
Wihel Altai
Department of Civil Engineering and Applied Mechanics, McGill University, 817 Sherbrooke St. West, Montreal, Quebec H3A0C3, Canada

ABSTRAKT

Simulations of turbulent interfaces produced by positive and negative buoyancy are conducted by moving blocks of vorticity and buoyancy in the direction of the flow. The second moment of the blocks increases at a rate proportional to the diffusivity. The block simulation has been shown to be relatively free of numerical oscillations. Unlike most classical methods, the error associated with Lagrangian block simulation (LBS) is not cumulative. Artificial diffusion error is negligible. This relatively non-diffusive LBS method is employed to simulate buoyancy at turbulence interfaces that are under the stabilizing and destabilizing influences by the force of buoyancy. In one series of simulation, the turbulence is initiated by shear and subjected to the stabilizing influence of the buoyancy force. In the other series, turbulence is produced by the destabilizing influence of the buoyancy force. The two series of simulations are evaluated to compare performance between (i) the large eddy simulation (LES) method and (ii) the K -ε modeling of turbulent flow.