Computational Analysis of the Blade Number Effect on the Performance of a Ducted Propeller

Ducted propellers were found to provide higher propulsive efficiency and operational safety than unducted propellers. The goal of our study is to optimize a ducted propeller design for propulsion of small rotorcrafts. In the paper, the effect of a number of blades on the flow structure around a ducted propeller and in its wake is analyzed by conducting flow simulations. Results are reported for propellers containing from two to five blades. Propeller designs with and without duct are compared. Simulations were conducted using Menter’s Shear Stress Transport version of the k-ω turbulence model implemented in the commercial CFD software Star-CCM+. The sensitivity analysis of simulation results to the grid resolution and the time step of simulations is presented.