dc.contributor.advisor Ott, Edward en_US dc.contributor.author Tsang, Yue-Kin en_US dc.date.accessioned 2004-08-27T05:22:27Z dc.date.available 2004-08-27T05:22:27Z dc.date.issued 2004-07-27 en_US dc.identifier.uri http://hdl.handle.net/1903/1735 dc.description.abstract We consider the enstrophy cascade in forced two-dimensional turbulence with a linear drag force. In the presence of linear drag, the energy wavenumber spectrum drops with a power law faster than in the case without drag, and the vorticity field becomes intermittent, as shown by the anomalous scaling of the vorticity structure functions. Using a previous theory, we compare numerical simulation results with predictions for the power law exponent of the energy wavenumber spectrum and the scaling exponents of the vorticity structure functions $\zeta_{2q}$ obtained in terms of the distribution of finite time Lyapunov exponents. We also study, both by numerical experiment and theoretic al analysis, the multifractal structure of the viscous enstrophy dissipation in terms of its R\'{e}nyi dimension spectrum $D_q$ and singularity spectrum $f(\alpha)$. We derive a relation between $D_q$ and $\zeta_{2q}$, and discuss its relevance to a version of the refined similarity hypothesis. In addition, we obtain and compare theoretically and numerically derived results for the dependence on separation $r$ of the probability distribution of $\delta_{\V{r}}\omega$, the difference between the vorticity at two points separated by a distance $r$. Our numerical simulations are done on a $4096 \times 4096$ grid. en_US dc.format.extent 6220981 bytes dc.format.mimetype application/pdf dc.language.iso en_US dc.title Two-dimensional Turbulence with Drag en_US dc.type Dissertation en_US dc.contributor.publisher Digital Repository at the University of Maryland en_US dc.contributor.publisher University of Maryland (College Park, Md.) en_US dc.contributor.department Physics en_US dc.subject.pqcontrolled Physics, Fluid and Plasma en_US dc.subject.pqcontrolled Physics, Atmospheric Science en_US dc.subject.pqcontrolled Physics, General en_US
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