Local dissipation limits the dynamics of impacting droplets on smooth and rough substrates

Abstract

A droplet that impacts onto a solid substrate deforms in a complex dynamics. To extract the principal mechanisms that dominate this dynamics we deploy numerical simulations based on the phase field method. Direct comparison with experiments suggests that a dissipation local to the contact line limits the droplet spreading dynamics and its scaled maximum spreading radius ${\beta }_{\max }$. By assuming linear response through a drag force at the contact line, our simulations rationalize experimental observations for droplet impact on both smooth and rough substrates, measured through a single contact line friction parameter ${\mu }_f$. Moreover, our analysis shows that at low and intermediate impact speeds dissipation at the contact line limits the dynamics and we describe ${\beta }_{\max }$ by the scaling law ${\beta }_{\max }\sim (Re{\mu }_{\mathrm{l}}/{\mu }_f{)}^{1/2}$ that is a function of the droplet viscosity (${\mu }_{\mathrm{l}}$) and its Reynolds number ($Re$).

References in corpus (2)

• Drop Splashing on a Dry Smooth Surface
• Compressible Air Entrapment in High-Speed Drop Impacts on Solid Surfaces

Cited by in corpus (1)

• Droplet impact on surfaces with asymmetric microscopic features