Thin Liquid Film Dynamics and Heat Transfer

Thin liquid films arise in contexts ranging from industrial evaporators and microfluidic devices to biological systems and functional coatings. Their dynamics are governed by an interplay of viscous forces, surface tension, inertia and interaction with solid substrates. Instabilities such as wave formation, bead‐like structures and film rupture dictate mass and heat transport and can be harnessed for applications in heat exchangers, soft material fabrication and separation processes. Heat transfer within these films depends critically on film thickness, wave topology and local mixing induced by unsteady flows. Advances in experimental imaging and simulation have revealed how microscopic fluctuations and interfacial phenomena influence macroscopic thermal performance, enabling optimisation of film stability, enhancement of heat‐transfer coefficients and the design of structured surfaces through controlled instabilities.

Research from Nature Portfolio

Recent studies have revisited the classical Plateau–Rayleigh instability in the context of liquid coatings on fibres, demonstrating that the growth rate of interfacial undulations can be tuned by varying the hydrodynamic boundary condition at the solid–liquid interface. Incorporating slip into thin‐film theory has provided a quantitative tool to extract slip lengths and predict instability dynamics with high fidelity. In parallel, work on polymeric liquid films has shown that fluid‐driven instabilities can be harnessed to fabricate periodic soft materials. By controlling Rayleigh–Taylor–type instabilities in thin polymer layers, researchers have achieved spontaneous formation of droplet lattices that, upon curing, yield durable microstructured surfaces with applications in photonic and mechanical metamaterials.

Thin Liquid Film Dynamics and Heat Transfer publication trend

The graph below shows the total number of articles in thin liquid film dynamics and heat transfer across all publications each year (not limited to Nature Index journals).

Technical terms

Reynolds number: Dimensionless ratio of inertial to viscous forces governing flow regime.

Nusselt number: Dimensionless heat‐transfer coefficient expressing convective transport relative to conduction.

Plateau–Rayleigh instability: Instability leading to breakup of liquid columns or films into droplets.

Slip length: Virtual distance within a solid at which the fluid velocity would extrapolate to zero, quantifying interfacial slip.

Heat‐transfer coefficient: Measure of heat flux per unit area and per unit temperature difference between surface and fluid.

References

1. Influence of slip on the Plateau–Rayleigh instability on a fibre. Nature Communications (2015).
2. Designing soft materials with interfacial instabilities in liquid films. Nature Communications (2018).
3. An experimental study of spatiotemporally resolved heat transfer in thin liquid-film flows falling over an inclined heated foil. International Journal of Heat and Mass Transfer (2016).
4. Solitary waves on falling liquid films in the inertia-dominated regime. Journal of Fluid Mechanics (2018).
5. Flow behaviour of drop and jet modes of a laminar falling film on horizontal tubes. International Journal of Heat and Mass Transfer (2018).