Abstract:
This thesis investigates the vortex interactions between a flapping airfoil and an oscillating cylinder, focusing on how the upstream cylinder’s presence influences the airfoil’s
thrust performance as it moves through the wake. The research examines the impact
of oscillatory motion of cylinder on the thrust and side force metrics of the flapping
airfoil while also assessing the effects of the flapping airfoil on the dynamics of cylinder.
A series of CFD simulations were conducted using ANSYS Fluent 2023 R1, utilizing
Overset meshing to enhance accuracy and avoid mesh deformation around both the airfoil and cylinder. Initial simulations established a baseline for the airfoil’s performance
across various parameters. The results showed that vortices from the upstream oscillating cylinder significantly affected the airfoil’s aerodynamic performance, with increasing pitching amplitude generally enhancing thrust and side force coefficients at lower
Strouhal numbers. However, higher Strouhal numbers resulted in diminishing returns,
indicating potential thresholds where further increases in pitching amplitude no longer
yield proportional benefits. The study also revealed change in dynamics in the VIV
of the cylinder, with drag coefficients consistently rising and lift coefficients decreasing
as Strouhal numbers increased. The findings also indicated that the oscillating airfoil
influenced the cylinder’s dynamics through external aerodynamic forces, affecting both
drag and lift and altering the cylinder’s oscillatory behavior. These insights highlight
the complexity of fluid-structure interactions and offer valuable guidance for designing
more efficient airfoil systems across various engineering applications, emphasizing the
reciprocal nature of the flapping airfoil and the oscillating cylinder.
