Year: 2026
Type: article
Abstract: The addition of a small amount of long-chain polymers confers viscoelastic properties to Newtonian flows. The resulting non-Newtonian solution now exhibits a different dynamics, such as enhanced mixing at low Reynolds number, where elastic instabilities can trigger elastic turbulence even though inertial turbulence is absent. Here, we study this phenomenon in viscoelastic planar jets and, in particular, we do it from the perspective of coherent structures to understand how elastic turbulence is triggered and sustained, which remain barely explored in this set-up. We introduce the spatio-temporal Koopman decomposition for extracting the dominant flow patterns, and we compare them with those from Newtonian planar jets at high Reynolds number. Global flow structures are similar between jets, with low-frequency streaks and high-frequency wave packets dominating the turbulent dynamics. However, structures are strikingly different in the near field, where elasticity-driven streaks affect the dynamics in the potential core of the viscoelastic planar jet, modifying the bulk flow and interacting with the flow instability. The analysis of the polymer field reveals stretched polymer filaments and centre-mode structures, which support the implication of the near-field streaks sustaining elastic turbulence in three-dimensional viscoelastic planar jets.
Source: Journal of Fluid Mechanics
Language: English
Subfield: Fluid Flow and Transfer Processes
Field: Chemical Engineering
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,550
Awards: G103507813, G1105844351, G1175115578, G1272900390, G1284337424, G1455481585, G1876177463, Connecting elastic and inertial polymeric turbulence, G1938719665, G1968185750, G2262748287, G2742980182, G2875277374, G300979063, G3480869486, G425668148, G4278938174, G464105488, G491712853, G5080475149, G5209569390, G5635532810, G586857820, G6273750484, G6506861008, G6586155961, G7084143925, 繊毛構造上で生じる粘弾性流れ: キャノピー内での弾性乱流, 古代説話における諸寺縁起の研究, G7805626310, G7863371703, G8497050386
OpenAlex ID: W7162787288