First coherent structure in elasto-inertial turbulence

Abstract

Elastoinertial turbulence (EIT) is a state of chaos found in wall-bounded flows with polymer additives over a large range of Reynolds numbers. Although the existence of EIT at subcritical Reynolds numbers is proof that complex polymer dynamics drive chaos, the exact mechanism remains poorly understood. The first coherent structure of EIT, shaped like its name, arrowhead, has been identified in two-dimensional channel flows and can be made to become perfectly steady and symmetrical. Its dynamics holds critical clues about the physics that drive or inhibit chaos in EIT flows.