Four-winged flapping flyer in forward flight

TL;DR

This study experimentally investigates a four-winged flapping flyer with flexible wings, analyzing how flapping frequency and phase lag affect speed and energy efficiency, revealing different optimal conditions for speed and power consumption.

Contribution

It introduces an experimental analysis of four-winged flapping flight with flexible wings, exploring the effects of kinematic parameters on performance and efficiency.

Findings

Optimal phase-lags differ for maximum speed and minimum energy consumption.

Flexible wings and phase dynamics significantly influence flight performance.

Performance maps show distinct regimes for speed and efficiency optimization.

Abstract

We study experimentally a four-winged flapping flyer with chord-wise flexible wings in a self-propelled setup. For a given physical configuration of the flyer (i.e. fixed distance between the forewing and hindwing pairs and fixed wing flexibility), we explore the kinematic parameter space constituted by the flapping frequency and the forewing-hindwing phase lag. Cruising speed and consumed electric power measurements are performed for each point in the $(f,\varphi)$ parameter space and allow us to discuss the problem of performance and efficiency in four-winged flapping flight. We show that different phase-lags are needed for the system to be optimised for fastest flight or lowest energy consumption. A conjecture of the underlying mechanism is proposed in terms of the coupled dynamics of the forewing-hindwing phase lag and the deformation kinematics of the flexible wings.