Numerical analysis of the wake flow field around ducted propellers/propellers under small-angle oblique flow

Abstract

To study the wake field characteristics around ducted propellers/propellers under a small oblique flow (15° and 30°) with typical inlet velocity coefficient J=0.4, this paper adopts unsteady wake vortices simulation for simulation analysis, which combines delayed detached eddy simulation and sliding mesh technology. Numerical simulation results show that, with the increase in the inlet angle, the propellers are not like ducted propellers protected by the outer ducts, for which the corresponding wake is greatly influenced by the angle. Moreover, the propellers experience more intense interaction between the blade tip vortex and the hub vortex and a more complex vortex structure of the wake flow field in comparison with the ducted propellers. An analysis of the turbulent kinetic energy in the wake flow field shows that the turbulent kinetic energy of ducted propellers is slightly lower than that of the propellers, as part of it is converted into the thrust of the ducted propellers.