On the aeroelastic energy transfer from a Lamb dipole to a flexible cantilever

Abstract

This paper studies the aeroelastic energy transfer from an advecting Lamb dipole to a flexible cantilever. The cantilever is initially placed either along or against the dipole's advection direction with various lateral distances. As the dipole moves towards the cantilever, they interact and exchange the energy. Such a fluid–structure interaction problem is numerically solved at a low Reynolds number of 200 using a lattice Boltzmann method based numerical framework. The simulation results confirm that, when the lateral distance is around the dipole radius, placing the cantilever against the dipole's advection direction is more favorable for energy transfer. Under this setting, the cantilever generally experiences two notable increases in its mechanical energy. The first one is caused by the direct impact associated with the dipole's approach, whereas the second one occurs when the dipole just passes by and exerts suction on the cantilever's free end. Each increase leads to a peak, and the second peak is much larger representing the maximum transferred energy. It is further found that when the lateral distance is about a half of the dipole radius, the cantilever's length is about one dipole radius, and its bending stiffness is moderate, the aeroelastic efficiency can be as high as 10.6%.