Decaying grid-generated turbulence in a rotating tank Export

@article{citeulike:1397161, abstract = {The decay of initially three-dimensional homogeneous turbulence in a rotating frame is experimentally investigated. Turbulence is generated by rapidly towing a grid in a rotating water tank, and the velocity field in a plane perpendicular to the rotation axis is measured by means of particle image velocimetry. During the decay, strong cyclonic coherent vortices emerge, as the result of enhanced stretching of the cyclonic vorticity by the background rotation, and the selective instability of the anticyclonic vorticity by the Coriolis force. This asymmetry towards cyclonic vorticity grows on a time scale \&\#150;1 ( is the rotation rate), until the friction from the Ekman layers becomes dominant. The energy spectrum perpendicular to the rotation axis becomes steeper as the instantaneous Rossby number Ro=/2 decreases below the value 2\&\#177;0.5 ( is the root-mean square of the vertical vorticity). The spectral exponent increases in time from its classical Kolmogorov value 5/3 up to values larger than 2. Below the threshold Ro\<2, the velocity derivative skewness decreases as |S|Ro, reflecting the inhibition of the energy transfers by the background rotation, with a net inverse energy cascade that develops at large scales. \©2005 American Institute of Physics}, author = {Morize, C. and Moisy, F. and Rabaud, M.}, citeulike-article-id = {1397161}, citeulike-linkout-0 = {http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PHFLE6000017000009095105000001&idtype=cvips&gifs=yes}, citeulike-linkout-1 = {http://link.aip.org/link/?PHF/17/095105}, citeulike-linkout-2 = {http://dx.doi.org/10.1063/1.2046710}, doi = {10.1063/1.2046710}, journal = {Physics of Fluids}, keywords = {decay, rotation}, number = {9}, posted-at = {2007-06-18 16:03:17}, priority = {3}, publisher = {AIP}, title = {Decaying grid-generated turbulence in a rotating tank}, url = {http://dx.doi.org/10.1063/1.2046710}, volume = {17}, year = {2005} }

TY - JOUR ID - citeulike:1397161 L3 - citeulike-article-id:1397161 N2 - The decay of initially three-dimensional homogeneous turbulence in a rotating frame is experimentally investigated. Turbulence is generated by rapidly towing a grid in a rotating water tank, and the velocity field in a plane perpendicular to the rotation axis is measured by means of particle image velocimetry. During the decay, strong cyclonic coherent vortices emerge, as the result of enhanced stretching of the cyclonic vorticity by the background rotation, and the selective instability of the anticyclonic vorticity by the Coriolis force. This asymmetry towards cyclonic vorticity grows on a time scale –1 ( is the rotation rate), until the friction from the Ekman layers becomes dominant. The energy spectrum perpendicular to the rotation axis becomes steeper as the instantaneous Rossby number Ro=/2 decreases below the value 2±0.5 ( is the root-mean square of the vertical vorticity). The spectral exponent increases in time from its classical Kolmogorov value 5/3 up to values larger than 2. Below the threshold Ro<2, the velocity derivative skewness decreases as |S|Ro, reflecting the inhibition of the energy transfers by the background rotation, with a net inverse energy cascade that develops at large scales. ©2005 American Institute of Physics IS - 9 JF - Physics of Fluids TI - Decaying grid-generated turbulence in a rotating tank PB - AIP VL - 17 KW - decay KW - rotation AU - Morize, C AU - Moisy, F AU - Rabaud, M PY - 2005/// UR - http://dx.doi.org/10.1063/1.2046710 ER -