Nonhomogeneous elastic turbulence in the two-dimensional Taylor-Couette flow

Abstract

Elastic turbulence is a spatially and temporally disordered flow state appearing in viscoelastic fluids at vanishing fluid inertia and large elasticity. The resulting flows have broad technological interest, particularly to enhance mixing and heat transfer in microdevices. Although its experimental characterization is now well established in different setups, its theoretical understanding and numerical reproducibility remain challenging, especially in wall-bounded geometries. By means of numerical simulations, we investigate the onset of elastic turbulence and the characteristics of the developed turbulent-like states in the two-dimensional, confined, Taylor-Couette system. First, we characterize the purely elastic instability, addressing previously contrasting evidences. We then show that the fully nonlinear dynamics are weakly anisotropic and strongly nonhomogeneous. Indeed, they are confined in a dynamically active region adjacent to the inner wall, akin to the elastic boundary layer from previous predictions. Within this region,in spite of some non-negligible deviations due to the nonhomeogeneity of our setup, the statistical and spectral turbulent properties are to reasonable extent not far from the theoretical expectations and experimental observations.