We work on the modeling of propeller flows using the Boundary Element Method (BEM). Compared to Navier-Stokes simulations, BEM provides a reduced-order model that is desirable for propeller design. However, the flow separation at the round (or non-zero) trailing edge of realistic propellers cannot be incorporated. To resolve this issue, We developed an iterative scheme, coupled with BEM, to model the flow separation zone by a properly extended sharp trailing edge. The predictions from the developed approach achieve favorable agreement with the experimental measurements and Navier-Stokes simulations.