Exit time of colloidal particles from falling drops

This work investigates the influence of convective transport within a sedimenting drop on the exit time of a colloidal particle. Using Brownian dynamics simulations, we compute exit times for particles originating from various locations inside the drop over a range of Péclet numbers (Pe). The Péclet number quantifies the balance between the convective transport, caused by the Hadamard-Rybczynski flow field within a sedimenting drop, and the thermal fluctuations in the system. Additionally, we model the exit time as a first-passage process governed by the backward Kolmogorov equation, solving it asymptotically for Pe≪1 and Pe≫1, as well as numerically, to determine the mean exit time as a function of Pe.