Design of a mechanism for experimental bench testing with rotating blades

Abstract

This research project represents the initial step of a project that will propose the development of an electromechanical mechanism for application in experimental bench testing with rotating blades built in dynamic scale. The mechanism will be equipped with flexible blades to study the effect of centrifugal forces on the apparent stiffness of the blades, which produces an increase in the resonance frequencies of the blades vibration modes. Such a mechanism is suitable to be used in experimental bench testings to study the aeroelastic behavior of a set of elastic blades in hovering flight. The main activity proposed in this project regards the sizing of a electrical motor based on the calculation of the torque required to drive the rotor axis, as well as the designing and structural analysis of the structural and mechanical components of the mechanism. Both aerodynamic torque and mechanical power will be obtained from the Blade Element Momentum theory, which enables the approximate calculation of the aerodynamic load (distributed force and momentum) stemmed from the wake induced by the rotating blades. The calculation will take into account variations in both number and dimensions of the blades, as well as the rotor rotational speed, in order to set critical conditions for using the equipment and define key parameters for designing the mechanism.