DESIGN AND OPTIMIZATION OF AN AIRCRAFT PROPELLER FOR TUNED TORSIONAL VIBRATION DAMPING

This paper analyzes the design process of an aircraft propeller for a piston engine. The propeller should also damp the main critical torsional frequency of the crankshaft. The first step was the calculation of the geometrical parameters of two different blades: one according to Larrabee's procedure and the other one according to the Theodorsen's theory. The evaluation of the effect of aerodynamics and centrifugal loads has required the union of the results come from CFD (Computational Fluid Dynamics) and the ones come from the CSM (Computational Structural Mechanics), through the execution of several one way FSI (Fluid Structure Interaction) analyses. The results allowed making pre-stressed modal analyses, which gave the opportunity to identify the kinds of propeller having the fundamental frequency coincident with the main resonance frequency of the crankshaft. The final design is a blade having the deformed shape of the optimum aerodynamic design.