DOI: 10.1615/ICHMT.2012.ProcSevIntSympTurbHeatTransfPal
ISBN Print: 978-1-56700-302-4
ISSN: 2377-2816
Analysis of DNS and RANS data in a turbulent channel flow with surface mounted ribs
Краткое описание
Turbulent channel flow with surface mounted ribs on both sides of the channel was investigated by means of DNS and RANS simulations. The ribs are of square cross-section of size r = 0.1h (h being the channel half-width) and a streamwise pitch of 8r. The bulk Reynolds number was 5056. The present DNS revealed that large pockets of intense streamwise velocity fluctuations, and the occurrence of quasi-streamwise coherent streaks, were responsible for the higher turbulence levels in the shear-layers behind the ribs. In addition, the local skin-friction coefficient in the DNS indicated that the separated flow behind a rib does not re-attach on to the wall. On comparing the present DNS and RANS results, it was apparent that the standard k − ε model overpredicted the turbulent kinetic energy by a notable margin. On the contrary, the results from RNG and realizable k − ε models were in reasonably good agreement with the DNS.