2
Department of Mechanical Engineering,Tabriz University
Abstract
This paper describes a design methodology for ducted propellers operating in a non-uniform
wake eld. An improved lifting line model is used to represent propeller blades where more realistic
slipstream deformation behind the propeller is considered, while the duct and hub are modeled by ring vortex
distributions. Duct and hub geometries are assumed to be known and their e ects on the propeller are
calculated during propeller design stage. At the same time, mutual interaction between duct/hub geometry
and propeller is taken into consideration based on an iterative procedure. For numerical application of the
present method, a design example is carried out and the e ect of slipstream deformation is investigated in
detail. Another application based on experimental work is also taken into account to present the accuracy
of the calculated results by present method and Computational Fluid Dynamics (CFD) code. Finally,
propulsive characteristics of ducted propellers obtained from present method are compared to those of
CFD code and experimental results.
)