Effect of aspect ratio on the propulsive performance of tandem flapping foils

Abstract

In this work, we describe the impact of aspect ratio ( $AR$ ) on the performance of optimally phased, identical flapping flippers in a tandem configuration. Three-dimensional simulations are performed for seven sets of single and tandem finite foils at a moderate Reynolds number, with thrust producing, heave-to-pitch coupled kinematics. Increasing slenderness (or $AR$ ) is found to improve thrust coefficients and thrust augmentation but the benefits level off towards higher values of $AR$ . However, the propulsive efficiency shows no significant change with increasing $AR$ , while the hind foil outperforms the single by a small margin. Further analysis of the spanwise development and propagation of vortical structures allows us to gain some insights into the mechanisms of these wake interactions and provide valuable information for the design of novel biomimetic propulsion systems.

Effect of Frequency–Amplitude Parameter and Aspect Ratio on Propulsion Performance of Underwater Flapping-Foil

“…Tang et al [ 24 ] carried out a numerical study on the self-propulsion of 3D flutter flexible plates in stationary fluid by combining the immersion boundary lattice Boltzmann method and the finite element method, pointing out that proper structural flexibility can improve the propulsion speed and efficiency. Lagopoulos et al [ 25 ] revealed that increasing the aspect ratio can improve thrust coefficients and thrust augmentation by using a three-dimensional numerical simulation method. Kumar et al [ 26 ] used the fluid module of the ANSYS software to calculate the thrust generated by the active flapping motion in short waves.…”