Work

Effect of elasto–inertial instabilities on heat transfer in Taylor–Couette flow

Year: 2026

Type: article

Abstract: Viscoelastic fluids in torsional shearing flows such as the Taylor–Couette (TC) geometry undergo elasto–inertial instabilities at Reynolds numbers far below the critical values required for the onset of classical inertial Taylor vortices in Newtonian liquids. While these instabilities are known to strongly modify momentum transport, their impact on thermal transport in complex fluids has been explored only in a few specific geometries. Here, we introduce a local heat transfer measurement technique that integrates a calibrated, surface-mounted heat-flux sensor into the outer cylinder of a wide-gap TC apparatus. Using a lumped-capacitance model to describe the sensor thermal response, we extract the local convective heat transfer coefficient over a wide range of Reynolds and Weissenberg numbers and across laminar, elasto–inertial, and turbulent-like regimes. For the Newtonian solvent, the measured Nusselt number follows the classical annular correlations of Childs and Long Childs and Long (1996) for rotating cylinders when expressed in terms of a modified Taylor number that accounts for geometry specific effects. In contrast, dilute polyisobutylene (PIB) solutions exhibit enhanced heat transfer, earlier flow transitions to unsteady states at Reynolds numbers an order of magnitude below the Newtonian Taylor-vortex threshold, and stronger variation in the Nusselt number ( N u ) characterizing the thermal energy transport away from the heated surface. The onset of this enhanced heat transfer rate coincides with torque-based signatures of elasto–inertial instability. Together, these results establish a clear link between polymer elasticity, secondary flow structures, and local convective heat transfer in Taylor–Couette flow, as well as demonstrating how elasto–inertial instabilities can be harnessed to enhance thermal transport in complex fluids at comparatively low Reynolds numbers.

Source: Journal of Non-Newtonian Fluid Mechanics

DOI: 10.1016/j.jnnfm.2026.105654

Authors: Rishabh V. More, Eugene Pashkovski, Reid Patterson, Gareth H. McKinley

Institutions: Monash University, Lubrizol (United States), Massachusetts Institute of Technology

Language: English

Topic: Rheology and Fluid Dynamics Studies

Subfield: Fluid Flow and Transfer Processes

Field: Chemical Engineering

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $3,010

Funder: Lubrizol