Turbulence Heat and Mass Transfer 6. Proceedings of the Sixth International Symposium On Turbulence Heat and Mass Transfer
DOI: 10.1615/ICHMT.2009.TurbulHeatMassTransf
ISBN Print: 978-1-56700-262-1
ISSN: 2377-2816
Inertial range similarity for velocity and scalar spectra in a turbulent channel flow
page 8
DOI: 10.1615/ICHMT.2009.TurbulHeatMassTransf.1990
ABSTRACT
Velocity and scalar spectra in a turbulent channel flow are examined using DNS databases with passive scalar transport (h+=180, 395, 640 and 1020 at Pr=0.71). Particular attention has been given to both kx and kz spectra in the outer region. In contrast to previous findings in the literature, the −5/3 power law does not hold for either velocity or scalar kx spectra over the present h+ range. For the kz spectrum, the scaling range slope of the θ spectrum is, however, closer to −5/3 than that of the u spectrum. This behaviour is most likely associated with large-scale spanwise mixing of θ.