Universality and Scaling Behaviour of Injected Power in Elastic Turbulence in Worm-like Micellar Gel

TL;DR

This study investigates the statistical properties of power fluctuations in elastic turbulence within worm-like micellar gels, revealing universal distribution patterns and flow characteristics similar to polymer solutions.

Contribution

It demonstrates that the power fluctuation distributions follow a universal large deviation form, specifically the Generalized Gumbel distribution, in elastic turbulence of micellar gels.

Findings

Power fluctuations exhibit non-Gaussian distributions.

Power spectrum shows a power-law decay.

Flow is spatially smooth but temporally random.

Abstract

We study the statistical properties of spatially averaged global injected power fluctuations for Taylor-Couette flow of a worm-like micellar gel formed by surfactant CTAT. At sufficiently high Weissenberg numbers (Wi) the shear rate and hence the injected power p(t) at a constant applied stress shows large irregular fluctuations in time. The nature of the probability distribution function (pdf) of p(t) and the power-law decay of its power spectrum are very similar to that observed in recent studies of elastic turbulence for polymer solutions. Remarkably, these non-Gaussian pdfs can be well described by an universal large deviation functional form given by the Generalized Gumbel (GG) distribution observed in the context of spatially averaged global measures in diverse classes of highly correlated systems. We show by in-situ rheology and polarized light scattering experiments that in the elastic turbulent regime the flow is spatially smooth but random in time, in agreement with a recent hypothesis for elastic turbulence.