Large is different: Nonmonotonic behavior of elastic range scaling in polymeric turbulence at large Reynolds and Deborah numbers.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 36921045.
- Also identified by DOI 10.1126/sciadv.add3831 and PMC identifier 10017036.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
We use direct numerical simulations to study homogeneous and isotropic turbulent flows of dilute polymer solutions at high Reynolds and Deborah numbers. We find that for small wave numbers <i>k</i>, the kinetic energy spectrum shows Kolmogorov-like behavior that crosses over at a larger <i>k</i> to a novel, elastic scaling regime, <i>E</i>(<i>k</i>) ∼ <i>k</i><sup>-ξ</sup>, with ξ ≈ 2.3. We study the contribution of the polymers to the flux of kinetic energy through scales and find that it can be decomposed into two parts: one increase in effective viscous dissipation and a purely elastic contribution that dominates over the nonlinear flux in the range of <i>k</i> over which the elastic scaling is observed. The multiscale balance between the two fluxes determines the crossover wave number that depends nonmonotically on the Deborah number. Consistently, structure functions also show two scaling ranges, with intermittency present in both of them in equal measure.