Physics

Instability

Mechanics

Statistical physics

Shear flow

Artificial intelligence

Antiferromagnetism

Viscoelasticity

Materials science

Chaotic

Condensed matter physics

Flow (mathematics)

Computer science

Classical mechanics

Hexagonal lattice

Thermodynamics

Physical Review Letters

Viscoelastic flows transition from steady to time-dependent, chaotic dynamics under critical flow conditions, but the implications of geometric disorder for flow stability in these systems are unknown. Utilizing microfluidics, we flow a viscoelastic fluid through arrays of cylindrical pillars, which are perturbed from a hexagonal lattice with various degrees of geometric disorder. Small disorder, corresponding to ~ 10% of the lattice constant, delays the transition to higher flow speeds, while larger disorders exhibit near-complete suppression of chaotic velocity fluctuations. We show that the mechanism facilitating flow stability at high disorder is rooted in a shift from extension-dominated to shear-dominated flow type with increasing disorder.

Disorder Suppresses Chaos in Viscoelastic Flows