Some characteristics of small-scale turbulence in a turbulent duct flow
- 1 December 1991
- journal article
- research article
- Published by Cambridge University Press (CUP) in Journal of Fluid Mechanics
- Vol. 233, 369-388
- https://doi.org/10.1017/s0022112091000526
Abstract
The fine-scale structure of turbulence in a fully developed turbulent duct flow is examined by considering the three-dimensional velocity derivative field obtained from direct numerical simulations at two relatively small Reynolds numbers. The magnitudes of all mean-square derivatives (normalized by wall variables) increase with the Reynolds number, the increase being largest at the wall. These magnitudes are not consistent with the assumption of local isotropy except perhaps near the duct centre-line. When the assumption of local isotropy is relaxed to one of local axisymmetry, or invariance with respect to rotation about a coordinate axis (here chosen in the streamwise direction), satisfactory agreement is indicated by the data outside the wall region. Support for axisymmetry is demonstrated by anisotropy invariant maps of the dissipation and vorticity tensors. The departure from axisymmetry does not appear to be affected by the Reynolds number. Expressions are proposed for approximations to the average energy dissipation and components of the mean-square vorticity. These proposals should allow these quantities to be measured accurately, at least in the present flow.Keywords
This publication has 20 references indexed in Scilit:
- Locally axisymmetric turbulenceJournal of Fluid Mechanics, 1991
- Some experimental results on velocity and vorticity measurements in turbulent grid flows with controlled sign of mean helicityFluid Dynamics Research, 1991
- Reynolds-stress and dissipation-rate budgets in a turbulent channel flowJournal of Fluid Mechanics, 1988
- Correlation between the longitudinal velocity fluctuation and temperature fluctuation in the near-wall region of a turbulent boundary layerInternational Journal of Heat and Mass Transfer, 1988
- Characteristics of vorticity fluctuations in a turbulent wakeJournal of Fluid Mechanics, 1988
- Turbulent energy dissipation in a wakeJournal of Fluid Mechanics, 1987
- Temperature-dissipation measurements in a turbulent boundary layerJournal of Fluid Mechanics, 1987
- Assessment of local isotropy using measurements in a turbulent plane jetJournal of Fluid Mechanics, 1986
- The fine-scale structure of the turbulent velocity fieldJournal of Fluid Mechanics, 1978
- The structure of the viscous sublayer and the adjacent wall region in a turbulent channel flowJournal of Fluid Mechanics, 1974