Pinch-off location and time during 2D droplet impact onto a wetted stationary cylinder using the lattice Boltzmann method

Abstract

This paper focuses on pinch-off location and time during 2D droplet impact onto a wetted stationary cylinder using the lattice Boltzmann method. A general off-lattice boundary condition is implemented for the curved boundary. The boundary condition is examined by comparing the steady-state velocity profile of the Taylor–Couette flow with its analytical solution. Additionally, the spreading length of a droplet impacting a wetted stationary cylinder is shown to be in good agreement with the numerical data of the literature. In the results section, the effects of Reynolds, Weber, and Froude numbers, as well as the droplet/cylinder diameter ratio, on the pinch-off length and time are investigated. The simulations revealed that as the Froude number increases, the pinch-off time increases with a slope 1.39 times more than that of the pinch-off length decrease. Moreover, it is shown that the critical Weber number for onset of dripping process increases with increasing the Froude number or decreasing the Reynolds number.