Lattice Boltzmann modeling of droplet impact on moving superhydrophobic wall

In this paper, the non-orthogonal multiple-relaxation-time lattice Boltzmann method incorporating contact angle hysteresis is used to study droplets impacting moving superhydrophobic walls. It is found that the contact time depends on wall velocity and is independent of the Weber number, while the horizontal displacement and maximum spreading length are controlled by both the Weber number and wall velocity. Moreover, based on the evolution of kinetic energy, the contact time is divided into the spreading time, retraction time, and separation time. The spreading time and retraction time are independent of wall velocity, while the separation time depends upon wall velocity. In addition, the tangential force depends on both wall velocity and Weber number, while the normal force is independent of wall velocity but depends on the Weber number. These findings offer a deep insight into the dynamic characteristics of droplet impact on superhydrophobic walls.