A hierarchy of spatially localized, self-similar structures in turbulent pipe flow*

Using the data-driven wavelet decomposition (DDWD), we probe experimental data from the Princeton SuperPipe pipe flow facility at Re_τ = 12,000 for the presence of coherent structures. The DDWD has the unique feature that it produces spatially localized structures, as opposed to other analysis methods that produce spatially extended structures. When applied to the SuperPipe data, DDWD reveals a hierarchy of spatially localized structures that are self-similar in a certain range of scales. We will discuss this observation in detail.