Blade, tip and hub vortices topology on a rudder in the propeller wake

Abstract

The flow hydrodynamics induced by a propeller around a rudder placed in its wake is characterized by a complex coupling between the rotating pressure field within the stream tube and the pressure distribution induced by the rudder geometry, possibly enhanced by a non-zero rudder incidence. The in-phase topology evolution of blade, tip, and hub vortices changes accordingly to the resulting pressure gradient distribution. The objectives of the paper are to: • describe a methodology to estimate the phase-averaged skin friction vector field τ through the time history of the temperature on its surface. • apply the methodology to the temperature data measured by Temperature Sensitive Paint (TSP) on both the suction and pressure sides of a hydrofoil placed in a propeller wake. • investigate the Angle of Attack (AoA) influence on the skin friction topology on the rudder part within the stream tube to characterize the spatial signature of blade, tip and hub vortices. • numerically correlate the topology of the skin friction at the wall to the dynamics of the hub and tip vortex systems far from the wall with the support of DES simulations