Fluid turbulence is characterized by localized structure of multiple scales. Wavelet transforms are novel techniques which can be used to analyze localized data with multiple scales efficiently. Motivated by this congruence, we use wavelet transform to study the structure of turbulent flows. Wavelet transform is a generic term and we use, in particular, the continuous wavelet transform and the wavelet-packet transform.;We study the structure of scalar and vorticity fields using the continuous wavelet transform; assess wavelet-packet transform as a tool for data compression, and introduce a power-spectra and a filtering technique based on it. This filtering technique was used to pick out features of particular scales. Based on this delineation, three facets of the structure of turbulence--local isotropy, intermittency and the scaling of structure functions, were studied. The finite skewness of the temperature derivatives contradicts local isotropy and two conjectures that resolve this contradiction were examined and found to be invalid. We were unable to reproduce in detail the evidence which was previously presented for the intermittent nature of the fine-scales of turbulence. Three aspects of structure functions were investigated. We find that the assumption of Taylor's hypothesis affects the scaling of structure functions to some extent. The odd and even order structure function exponents have divergent behavior. Structure functions of small-scales are significantly affected by large scale.;Continuous wavelet transform is valuable for visualizing the structure of two-dimensional turbulent flows. The wavelet-packet transform is the best technique for characterizing one and two-dimensional turbulence data efficiently. The differences in Fourier and wavelet-packet power-spectra raise several questions about spectral analysis and wavelet-packet filtering is found to be a modest improvement over Fourier filtering. This thesis presents an assessment of the utility of wavelet transforms as well as a modestly improved understanding of the structure of turbulence.
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