Two-dimensional energy spectra in high Reynolds number turbulent boundary layers
| Autor: | Chandran, Dileep, Baidya, Rio, Monty, Jason P., Marusic, Ivan |
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| Rok vydání: | 2017 |
| Předmět: | |
| Zdroj: | J. Fluid Mech. (2017), vol. 826, R1 |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1017/jfm.2017.359 |
| Popis: | Here we report the measurements of two-dimensional (2-D) spectra of the streamwise velocity ($u$) in a high Reynolds number turbulent boundary layer. A novel experiment employing multiple hot-wire probes was carried out at friction Reynolds numbers ranging from 2400 to 26000. Taylor's frozen turbulence hypothesis is used to convert temporal-spanwise information into a 2-D spatial spectrum which shows the contribution of streamwise ($\lambda_x$) and spanwise ($\lambda_y$) length scales to the streamwise variance at a given wall height ($z$). At low Reynolds numbers, the shape of the 2-D spectra at a constant energy level shows $\lambda_y/z \sim (\lambda_x/z)^{1/2}$ behaviour at larger scales, which is in agreement with the existing literature at a matched Reynolds number obtained from direct numerical simulations. However, at high Reynolds numbers, it is observed that the square-root relationship tends towards a linear relationship ($\lambda_y \sim \lambda_x$) as required for self-similarity and predicted by the attached eddy hypothesis. Comment: 11 pages, 6 figures |
| Databáze: | arXiv |
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