Design and experimental verification of a locally resonant metamaterial applied to aeroelastic problems

• Grant number: 23/01222-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: July 01, 2024
• Status: Discontinued
• Field of knowledge: Engineering - Aerospace Engineering - Aerospace Structures
• Principal Investigator: Vagner Candido de Sousa
• Grantee: Mateus Fernandes Darini
• Host Institution: Faculdade de Engenharia. Universidade Estadual Paulista (UNESP). Campus Experimental São João da Boa Vista. São João da Boa Vista , SP, Brazil
• Associated scholarship(s): 24/18330-1 - Study of locally resonant metamaterials applied for aeroelastic problems, BE.EP.IC

Abstract

This work proposes an investigation in the field of the dynamics of rigid and elastic bodies and focuses in the elaboration, application and test of a structure typically known as locally resonant metamaterial, with the purpose of promoting passive control of aeroelastic oscillations (flow-induced vibrations exhibited by aerodynamic surfaces) in a classical airfoil. The airfoil under consideration has two degrees of freedom (translational and rotational displacements) and exhibits coupled motions that refer to the flexural-torsional deformations that would be observed in the wings of a conventional airplane when operating (inadvertently or for test purposes) at airflow speeds close to or above its critical flutter speed. The nature of the (coupled) motions introduces additional challenges since the more typical cases from the literature concerning with metamaterials involve specific behaviors (e.g., transverse vibrations of beams and plates). Another challenging factor is that the frequencies of the aeroelastic motions tend to change as the airflow speed changes, while the metamaterials tend to be designed for a prescribed target frequency. Despite the target frequency being very specific, a remarkable aspect of metamaterials is the capability of exhibiting a region of vibration attenuation that comprises a relatively wide frequency range. Such a region is known as bandgap, and the target frequency of the metamaterial corresponds to one of the boundaries of the bandgap (the lower or the upper boundary, depending on the case at hand). The appearing of a bandgap around the flutter frequency of an aerodynamic surface could be attractive and, therefore, is considered in this investigation. This work comprises the study and application of consolidated theories about vibrations, metamaterials and aeroelasticity, implementation of source-codes and execution of simulations, prototyping and experimental verification (wind tunnel tests) of an airfoil designed to incorporate characteristics of a locally resonant metamaterial.