Polymer additives are commonly used in pipeline transport of liquids such as crude oil transport, water heating and cooling systems, and airplane tank filling to reduce turbulent drag. The emergence of elastoinertial turbulence (EIT), a chaotic flow state resulting from the interplay between inertia and elasticity, sets a limit on the achievable drag reduction using polymer additives. We investigate the dynamics of EIT using Spectral Proper Orthogonal Decomposition (SPOD) and discover that the dynamics of EIT are predominantly made of a collection of self-similar nested traveling waves. Polymer sheets emerge at the critical layers of each wave, and they act like walls for the next (immediately faster) traveling wave, leading to a nested arrangement of waves.
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