THMT-12. Proceedings of the Seventh International Symposium On Turbulence Heat and Mass Transfer
DOI: 10.1615/ICHMT.2012.ProcSevIntSympTurbHeatTransfPal
ISBN Print: 978-1-56700-302-4
ISSN: 2377-2816
Turbulence structure in a rapidly accelerating channel flow
pages 480-485
DOI: 10.1615/ICHMT.2012.ProcSevIntSympTurbHeatTransfPal.530
ABSTRAKT
Direct Numerical Simulations of a turbulent channel flow subjected to mild and rapid temporal accelerations are carried out. The flow structures and some turbulent statistics obtained for the two flow excursions are compared. The results show elongation of streaks in the streamwise direction during the earlier stage of the ramp. A significant role of interaction of low-speed streaks and vortical structures is seen during this period. The prominent influence of ramp rate in the flow behavior is reflected in the big difference of friction coefficients in the rapid and the slower acceleration cases.