Turbulent boundary layer at low Reynolds number
TL;DR: The results of an experimental investigation of a turbulent boundary layer with zero-pressure gradient directed toward extending the data base at low Reynolds numbers are presented in this article, where the data obtained are concerned primarily with mean velocity distributions, skin-friction coefficients, and distributions of intensity of the longitudinal component of the turbulent velocity fluctuations for Reynolds numbers based on momentum thickness as low as 465.
Abstract: The results of an experimental investigation of a turbulent boundary layer with zero‐pressure gradient directed toward extending the data base at low Reynolds numbers are presented. The data obtained are concerned primarily with mean‐velocity distributions, skin‐friction coefficients, and distributions of intensity of the longitudinal‐component of the turbulent‐velocity fluctuations for Reynolds numbers based on momentum thickness as low as 465. The validity, at low Reynolds numbers, of the semi‐empirical laws characterizing the inner and outer regions of the boundary layer is examined.
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TL;DR: In this paper, the turbulent boundary layer on a flat plate, with zero pressure gradient, is simulated numerically at four stations between R sub theta = 225 and R sub tta = 1410.
Abstract: The turbulent boundary layer on a flat plate, with zero pressure gradient, is simulated numerically at four stations between R sub theta = 225 and R sub theta = 1410. The three-dimensional time-dependent Navier-Stokes equations are solved using a spectra method with up to about 10 to the 7th power grid points. Periodic spanwise and stream-wise conditions are applied, and a multiple-scale procedure is applied to approximate the slow streamwise growth of the boundary layer. The flow is studied, primarily, from a statistical point of view. The solutions are compared with experimental results. The scaling of the mean and turbulent quantities with Reynolds number is examined and compared with accepted laws, and the significant deviations are documented. The turbulence at the highest Reynolds number is studied in detail. The spectra are compared with various theoretical models. Reynolds-stress budget data are provided for turbulence-model testing.
1,934 citations
TL;DR: In this article, a method for generating three-dimensional, time-dependent turbulent inflow data for simulations of complex spatially developing boundary layers is described, which is essentially a variant of the Spalart method, optimized so that an existing inflow?outflow code can be converted to an inflow-generation device through the addition of one simple subroutine.
1,462 citations
TL;DR: In this article, a publisher's version of an article published in Journal of Fluid Mechanics © 2007 Cambridge University Press, Cambridge, UK. www.cambridge.edu.org/
Abstract: This is a publisher’s version of an article published in Journal of Fluid Mechanics © 2007 Cambridge University Press. www.cambridge.org/
1,197 citations
TL;DR: In this paper, a surface-layer field experiment with turbulence measurements at three levels (3, 6, and 14 m) and simultaneous profile data has been analyzed to yield information on flux-gradient relationships for wind and temperature.
Abstract: Previous results of non-dimensional wind and temperature profiles as functions of ζ(= z/L) show systematic deviations between different experiments. These discrepancies are generally believed not to reflect real differences but rather instrumental shortcomings. In particular, it is clear that flow distortion has not been adequately treated in most previous experiments. In the present paper, results are presented from a surface-layer field experiment where great care was taken to remove any effects from this kind of error and also to minimize other measuring errors. Data from about 90 30-min runs with turbulence measurements at three levels (3, 6, and 14 m) and simultaneous profile data have been analysed to yield information on flux-gradient relationships for wind and temperature.
890 citations
TL;DR: In this article, the authors used a low-speed, high-Reynolds-number facility and a high-resolution laser-Doppler anemometer to measure Reynolds stresses for a flat-plate turbulent boundary layer from Reθ = 1430 to 31 000.
Abstract: Despite extensive study, there remain significant questions about the Reynolds-number scaling of the zero-pressure-gradient flat-plate turbulent boundary layer. While the mean flow is generally accepted to follow the law of the wall, there is little consensus about the scaling of the Reynolds normal stresses, except that there are Reynolds-number effects even very close to the wall. Using a low-speed, high-Reynolds-number facility and a high-resolution laser-Doppler anemometer, we have measured Reynolds stresses for a flat-plate turbulent boundary layer from Reθ = 1430 to 31 000. Profiles of u′2, v′2, and u′v′ show reasonably good collapse with Reynolds number: u′2 in a new scaling, and v′2 and u′v′ in classic inner scaling. The log law provides a reasonably accurate universal profile for the mean velocity in the inner region.
776 citations