We model the slip length tribometer (SLT), originally presented by Pelz et al. (J. Fluid Mech., vol. 948, 2022, p. A8) in OpenFOAM. The plate tribometer is especially designed to simultaneously measure viscosity and slip length for lubrication gaps in the range of approximately 10 $\mathrm {\mu }$m at temperatures and surface roughnesses relevant to technical applications, with a temperature range of $-30$ to $100\,^\circ \mathrm {C}$ and surface roughness ranging from $10\ \mathrm {nm}$ to $1\ \mathrm {\mu }\mathrm {m}$. A simplified analytical model presented by Pelz et al. (J. Fluid Mech., vol. 948, 2022, p. A8) infers the slip length of the plate from the experimentally measured torque and the plate gap height. The present work verifies the analytical model using axisymmetric flow simulations and presents the effect of inlet on the numerical velocity profiles. The simulation results are in very good agreement with the results of the analytical model. The main conclusion drawn from this study is the validation of the Navier-slip boundary condition as an effective model for partial slip in computational fluid dynamics simulations and the negligible influence of the inlet on the fluid flow between the SLT's plates.