Bi-directional fluid-structure interaction for prediction of tip clearance influence on a composite ducted propeller

Compared to metals, composite materials have many advantages such as lightweight, high strength-to-weight ratio, and reduced noise properties. The anisotropic nature of carbon fiber reinforced plastic (CFRP) with different stacking sequences and fiber angles can be used to build a composite propeller with enhanced hydrodynamic and mechanical properties. The primary objective of this paper is to analyze the influence of the tip clearance on a composite ducted propeller using the bi-directional fluid-structure interaction (FSI) method. Several finite element models with different stacking sequences and ply orientations of the propeller are analyzed. An acceptable layup for the composite blade is found. A comparative study is presented to compare different tip clearances for the composite ducted propeller and with a metallic one. The change of thrust, torque, efficiency, pressure distribution, deformation and twist angle are presented. An optimized result for the gap-to-span ratio (GSP) 0.417 is selected as the best compromise between energy-saving and safety factor against damage.