Enhancing Thrust in Flapping Airfoils Through Wake Interactions with Oscillating Cylinder

TL;DR

This paper explores how the wake of an oscillating cylinder can enhance the thrust of a flapping airfoil, revealing relationships between flapping parameters and performance for potential optimization.

Contribution

It demonstrates that placing a flapping airfoil in the wake of an oscillating cylinder increases thrust and identifies key parameters influencing efficiency.

Findings

Thrust increases when airfoil is in the cylinder's wake.

Strouhal number correlates with pitching amplitude.

Optimization potential through parameter adjustment.

Abstract

Inspired by the natural motion of insects, fish, and other animals, flapping airfoils have gained significant importance due to their applications in fields such as ship propulsion, micro aerial vehicles, and autonomous underwater vehicles. Over the past two decades, extensive research has focused on understanding the dynamics of these airfoils, their thrust production capabilities, and methods to enhance this thrust in unsteady flows. This study investigates how the presence of a cylinder oscillating due to incoming flow affects the thrust performance of the flapping airfoil. The results indicate that the flapping airfoil generates increased thrust when placed in the wake of the oscillating cylinder compared to a scenario without the cylinder's wake. A direct relationship has been found between the strouhal number ($St$) of the flapping airfoil and its pitching amplitude, which significantly influences the airfoil's performance. This analysis highlights the potential for optimizing flapping airfoil efficiency through strategic selection of flapping parameters and the placement of an oscillating cylinder.