The Use of Viscoelastic Supports to Whirl Flutter Control in Aeroelastic Systems

Resumo

The search for greater flight efficiency and net-zero emissions has driven the need for new aircraft concepts. In this context, distributed electric propulsion (DEP) offers a promising approach by enabling alternative propulsion systems. Electric motors, in particular, allow for a wide range of possible propeller configurations. An example of this is NASA X-57 Maxwell test aircraft. However, this solution introduces structural challenges due to the potential for aeroelastic instabilities such as whirl flutter, a phenomenon that occurs when a system experiences gyroscopic effects caused by a rotating component coupled to a flexible structure. To mitigate these instabilities, this work proposes the use of viscoelastic supports (VES) in the coupling between the propeller and a typical section. Due to its characteristics, the use of VES tends to reduce the transmission of vibrations from the rotating parts to the surrounding structure. The VES will be modeled in the frequency domain, using a complex stiffness that depends on both frequency and operating temperature. The compose system (typical section and propulsion system) is modeled by 4 degree of freedom system and the numerical results obtained using MATLAB software. The viscoelastic stiffness is characterized considering both parameters (frequency and temperature), and its influence on the whirl flutter speed is evaluated.