Observations from poke-flow experiments were modeled with fluid dynamics simulations to determine the BB-SOA viscosity. The simulations were performed using the micro-fluidics module in COMSOL Multiphysics (v5.4). The following parameters were required as inputs: the particle's surface tension, the Navier slip length, and the contact angle. Conservative upper and lower limits for these parameters were used as inputs (Table ). The combination of these input parameters that yielded the highest and lowest viscosity outputs was used to obtain an upper and lower limit of viscosity.