The role of flow inhomogeneity in elastic turbulence

The addition of polymers to a Newtonian solvent can induce chaotic motion even at negligible inertia, resulting in a turbulence-like state known as Elastic Turbulence (ET)¹. Predominantly driven by experimental studies, ET research has recently seen advances through direct numerical simulations aimed at unveiling its intricate dynamics.

In our study we perform fully-resolved 3D numerical simulations of ET utilizing the Oldroyd-B model across three progressively more complex configurations: a triperiodic flow² (three homogeneous directions), a planar channel flow³ (two homogeneous directions), and a planar jet⁴ (only one homogeneous direction). For all configurations, we maintain a Reynolds number (representing the relative importance of inertia compared to viscosity) low enough to ensure a laminar state for the equivalent Newtonian fluid flow. Concurrently, we set a Deborah number (accounting for the ratio of the elastic and bulk-flow time scales) high enough to sustain a fully developed ET state.

This presentation will explore ET in increasingly inhomogeneous flow configurations, emphasizing the similarities and differences observed. Our findings contribute to a deeper understanding of ET dynamics compared to Newtonian turbulence, informing future experimental and numerical investigations.

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¹ Steinberg, Annu. Rev. Fluid Mech. 53 (2021).

² Singh et al., Nat. Commun. 15 (2024).

³ Foggi Rota et al., arXiv 2310.05340 (2023).

⁴ Soligo and Rosti, Int. J. Multiph. Flow 167 (2023).