A numerical approach to determine the optimum circulation distribution of a propeller inside a given duct 18 presented. The propeller blades are modelled by lifting lines. The duct is represented in non-linear theory by using a potential based panel method.

The propeller lifting lines are approximated by a finite number of vortex horseshoes. The strengths of the horseshoes are determined by using a numerical nonlinear optimization technique to maximize the propulsor efficiency. The non axisymmetric duct/propeller interactions are included within the design procedure.

Results are presented for propellers designed to operate at various thrust coefficients inside of two different ducts and at several advance ratios.

This content is only available via PDF.