Droplets on the liquid substrate: Thermocapillary oscillatory instability

The influence of heating on the shape and the dynamics of a droplet on a liquid substrate has been investigated. The problem is studied numerically in the framework of longwave amplitude equations. The effect of gravity is taken into account. We show that the thermocapillary stresses produce a significant deformation of droplet's interfaces. Heating the droplet from above can create an oscillatory instability generating periodic and quasiperiodic oscillations, change of the droplet shape, and the droplet's decomposition. Heating from below can lead to the substrate layer's rupture due to its monotonic instability.

Automated summary

The influence of heating on a droplet's shape and dynamics on a liquid substrate was investigated, showing that thermocapillary stresses significantly deform droplet interfaces. Heating from above can cause oscillatory instability, periodic and quasiperiodic oscillations, shape changes, and droplet decomposition, while heating from below can lead to substrate layer rupture.