3D Numerical simulations of the flow of a drop under the effects of a radial temperature gradient

ESCOBAR QUIROZ, J. F.; MANSILLA, R. A.; GOMBA, J. M.; PERAZZO, C. A.

Anales AFA

Asociación Física Argentina

Lugar: Tandil; Año: 2023

0327-358X

It has been shown experimentally that when a drop is deposited at the center of a substrate with an axialtemperature gradient (hotter in the center), thermocapillarity effects makes an outward flow to appear sothat the drop evolves towards a ring whose radius increases with time. Upon reaching a critical radius, thecontact line becomes unstable, showing gentle undulations whose amplitudes grow with time. Using thelubrication approximation and adopting appropriate dimensionless variables, a parameter-free differentialequation is obtained that governs this type of thermocapillary flow. Numerical solutions of this equationare presented to study the unstable stage. Experimental results are compared with those obtained fromthe numerical solutions.