DOI: 10.1615/ICHMT.2012.ProcSevIntSympTurbHeatTransfPal
ISBN Print: 978-1-56700-302-4
ISSN: 2377-2816
Second-order chemical reaction micro- and macromixing in a plane turbulent channel
ABSTRAKT
We analyze a database obtained from a direct numerical simulation of the reacting flow in a plane channel at low Reynolds number (Reτ = 180). The fluctuations of the concentration of the chemical species that react following a second-order chemical reaction (Da = 1, Sc = 0.7) are processed to determine the contribution of the large scale and small scale fluctuations along streamwise direction. The analysis is extended to educe the flow structures responsible for the large fluctuations of concentration. The conditional sampling technique used reveals that hairpin-shape vortices that convect flow from the walls towards the center of the channel produce the extreme fluctuations.