CORDIS - Forschungsergebnisse der EU
CORDIS

Atomistic to Molecular to Bulk Turbulence

Periodic Reporting for period 1 - ATM2BT (Atomistic to Molecular to Bulk Turbulence)

Berichtszeitraum: 2019-02-01 bis 2022-11-30

Plastic pollution affects societal health and wellbeing in multiple ways. There are a number of initiatives aimed at changing the way that plastics are designed, produced, used, disposed and reprocessed in the plastics chain. This proposal is an opportunity to bring together the concepts of plastic flow in solids and turbulence in fluids, that originates at the molecular level, thus showing the universality of the role of coherent structures in all three phases. Coherent structures can be thought of as the elementary constituent parts of turbulence, much in the same way as elementary particles, are the building blocks of atoms. What is so fascinating, are the strong similarities of turbulent states appearing in hydrodynamical flows and pattern formation in solid plasticity. Surprisingly, these systems are related through strikingly similar mathematics, as indicated by recent developments in gradient theory, which explored and established such a connection between fluid/solid dynamic, that has its roots, we believe, at the molecular level. We will use this inherent mathematical connection to help solve one of the significant problems in society today, namely the development of numerical codes applied to optimize the recycling process of reprocessed, eventually biodegradable, plastics. We have proposed a high-risk and ambitious pioneering project, to study the universal characteristics of pattern formation in turbulent hydrodynamics and solids in a single mathematically unified manner, that originates at the molecular level. The proposal promises to bridge multiple research areas, to create an interdisciplinary activity, with multiple basic, applied and research benefits.
Since the beginning of the project we have studied sheared Taylor-Couette flow of a viscous fluid confined in between two coaxial rotating cylinders presents, the quintessential model of boundary layer turbulence, in the wide gap approximation. We have also studied the alternative, the narrow gap approximation to the Taylor-Couette system. As is known, the flows curl around the axial symmetry line and show increasing perturbations closer to either boundary surface/layer. Expressed as a function of the inner and outer Reynolds numbers, and their respective rotational frequencies, the Rayleigh line and the linear stability boundary jointly define the linear stability (or unstability) regimes of such flows. We used here the sequence of bifurcations approach and we will be submitting for publication within March 2020.

We, AU and Akita, Kanasaki, employed a homotopy method in order to resolve the degeneracy due to resonance, which exists in fluid motion associated with a channel of infinite extent with Cartesian geometry. In this work we elucidate the mechanism by considering the particular case of laterally heated flow in the vertical configuration. The introduction of a symmetry breaking perturbation, in the form of a perturbative Poiseuille flow component as the simplest imperfection, alters substantially the resonant bifurcation tree of the original basic shear flow. Additionally, previously unknown resonant higher order, in the bifurcation tree, nonlinear solutions for the unperturbed flow, i.e. after removal of the imperfecting Poiseuille flow component, were discovered, without the implementation of classical stability analysis based on Floquet theory. These studies refers to the bulk property of fluids. We hope that we will elucidate on this results, by approaching the same calculations from the molecular side.

These two works are going to be submitted for publication within March 2020.
There are a number of initiatives, that ATM2BT is associated with, aimed at 1) changing the way that plastics are designed, produced, used, disposed and reprocessed in the plastics chain and 2) providing the ultimate theoretical background to a unified study of turbulence in multimedia.

ATM2BT is an opportunity to bring together the concepts of plastic flow in solids and turbulence in fluids and beyond, from the molecular level, thus showing the universality of the role of coherent structures in ALL phases. Coherent structures can be thought of as the elementary constituent parts of turbulence, much in the same way as elementary particles, are the building blocks of atoms. What is so fascinating, are the strong similarities of turbulent states appearing in hydrodynamical flows and pattern formation in solid plasticity. This will lead to the unified basis of the molecular level.

It has been identified, surprisingly, these systems are related through strikingly similar mathematics, as indicated by recent developments in gradient theory, which explored and established such a connection between fluid/solid dynamics. We will use, within ATM2BT, this inherent mathematical connection to help solve one of the significant problems in society today, namely the development of numerical codes applied to optimize the recycling process of reprocessed, eventually biodegradable, plastics. ATM2BT will additionally study the universal characteristics of pattern formation in turbulent hydrodynamics and solids in a single mathematically unified manner.

ATM2BT promises to bridge multiple research areas, will create an interdisciplinary activity, with multiple basic, applied and research benefits.

Plastic pollution affects societal health and wellbeing in multiple ways. An unconditional societal benefit of ATM2BT.

ATM2BT - project of scientific and humanitarian benefits in a large scale.
Temporal correlation as function of Reynolds number in the stochastic Taylor-Couette system