Aspect ratio effects in turbulent duct flows studied through direct numerical simulation

Characterization of Near-Wall Turbulent Flows by Tomographic Piv

“…Although it was mentioned that there are preferred angles for the main turbulent structures, the instantaneous flow displays a variety of vortex inclinations that can be found in the visualizations observed in the literature [Scarano and Poelma, 2009, Atkinson et al, 2011, Schröder et al, 2011, Foucaut et al, 2011a, Jodai et al, 2014, Vinuesa et al, 2014. Figure 2.3 shows coherent vortices, defined using the Q-criterion ( [Hunt et al, 1988]), from direct numerical simulation of a flow inside a duct of aspect ration of 3 with Re τ = 180 ( [Vinuesa et al, 2014]).…”

“…(b) Contour lines of the primary mean streamwise flow, and vectors of the secondary mean wall-normal and spanwise flows for the DNS of [Vinuesa et al, 2014]. Red rectangle refers to a similar region of the present tomo-PIV study.…”

“…Figure 2.3 shows coherent vortices, defined using the Q-criterion ( [Hunt et al, 1988]), from direct numerical simulation of a flow inside a duct of aspect ration of 3 with Re τ = 180 ( [Vinuesa et al, 2014]). …”

“…• in the outer region ( [Carlier and Stanislas, 2005, Ganapathisubramani et al, 2006, Gao et al, 2011), which Vinuesa et al, 2014]). Colour code by wall-normal direction: blue refers to vortices closer to the lower wall, while red to the ones closer to the upper wall.…”

“…Coherent vortices extracted from the direct numerical simulation of a flow inside a duct with Re τ = 180 ( [Vinuesa et al, 2014]). Colour code by wall-normal direction: blue refers to vortices closer to the lower wall, while red to the ones closer to the upper wall.…”