DIRECT NUMERICAL SIMULATION OF A THREE-DIMENSIONAL NATURAL-CONVECTION FLOW IN A DIFFERENTIALLY HEATED CAVITY OF ASPECT RATIO 4

Author: Soria M.   Trias F.   Pérez-Segarra C.   Oliva A.  

Publisher: Taylor & Francis Ltd

ISSN: 1521-0634

Source: Numerical Heat Transfer Part A: Applications, Vol.45, Iss.7, 2004-04, pp. : 649-673

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Abstract

The majority of the direct numerical simulations of turbulent and transition natural- convection flows in cavities assume two-dimensional behavior. To investigate the effect of the three-dimensional fluctuations, a complete direct numerical simulation has been carried out, in a cavity with aspect ratio 4, Ra z = 6.4 × 10 8 , and Pr = 0.71 , using a low-cost PC cluster. A description of the parallel algorithm and the methodology used to verify the code and the accuracy of the statistics obtained is presented. The main features of the two- and three-dimensional flows are described and compared. Several first- and second-order statistic distributions have been evaluated, including the Reynolds stress tensor. Significant differences are observed between the second-order statistics of the two- and three- dimensional simulations.