Viscoelastic Fluid Dynamics and Drag Reduction Techniques

Viscoelastic fluids display both viscous and elastic characteristics due to the presence of polymeric or particulate microstructures. Under flow, these materials can develop elastic instabilities even at low inertial forces, giving rise to phenomena such as elastic turbulence, characterised by chaotic fluctuations in velocity and enhanced mixing. The competition between viscous dissipation and polymeric elasticity governs flow behaviour, leading to modified energy spectra and unusual scale interactions. Drag reduction in turbulent and laminar flows is achieved by introducing long-chain polymers or surfactants, which alter the near‐wall dynamics, suppress turbulent eddies and diminish frictional losses. Techniques span from additive blending of drag‐reducing agents to geometrical optimisation of flow passages, such as nozzles or channels, where extensional and shear components are tuned to balance pressure drop and throughput. These strategies yield practical gains across industrial transport, heat exchangers, biomedical devices and additive manufacturing, emphasising the global significance of viscoelastic fluid dynamics.

Research from Nature Portfolio

Recent studies have revealed that elastic turbulence shares fundamental features with classical turbulence despite occurring at vanishing Reynolds numbers. Direct numerical simulations demonstrate dual power-law regimes in kinetic and polymeric energy spectra, and multifractal intermittency arising from the balance of viscous and elastic stresses. Another investigation into elastoviscoplastic fluids has uncovered a novel scaling range between inertial and dissipative scales as plasticity increases, alongside heightened intermittency linked to non‐Newtonian dissipation. These findings elucidate how elasticity and plasticity jointly shape turbulent spectra and extreme events, bearing implications for geophysical flows and industrial processes where complex fluids undergo high‐Reynolds‐number conditions.

Viscoelastic Fluid Dynamics and Drag Reduction Techniques publication trend

The graph below shows the total number of articles in viscoelastic fluid dynamics and drag reduction techniques across all publications each year (not limited to Nature Index journals).

Technical terms

Weissenberg number: Dimensionless ratio of fluid relaxation time to characteristic deformation time, indicating the prominence of elastic effects in flow.

Reynolds number: Ratio of inertial forces to viscous forces, determining whether flow regimes are laminar or turbulent.

Elastic turbulence: Chaotic flow state in viscoelastic fluids driven by elastic instabilities at low Reynolds numbers, leading to enhanced mixing.

Elastoviscoplastic fluids: Complex materials exhibiting coupled elastic, viscous and plastic responses under applied stress.

Drag-reducing polymers: High‐molecular‐weight additives that suppress turbulent fluctuations and reduce frictional resistance in fluid transport.

Extensional flow: Flow regime where fluid elements undergo stretching, crucial for characterising deformation in contractions and nozzles.

References

1. Intermittency in the not-so-smooth elastic turbulence. Nature Communications (2024).
2. Scaling and intermittency in turbulent flows of elastoviscoplastic fluids. Nature Physics (2023).
3. Purely elastic turbulence in pressure-driven channel flows. Proceedings of the National Academy of Sciences of the United States of America (2024).
4. Optimal shape design of printing nozzles for extrusion-based additive manufacturing. Additive Manufacturing (2024).
5. Research Progress on the Collaborative Drag Reduction Effect of Polymers and Surfactants. Materials (2020).