On the Shape Optimization of Flapping Wings and their Performance Analysis

TL;DR

This paper presents a method for optimizing flapping wing shapes to maximize propulsive efficiency using a gradient-based optimizer combined with UVLM, providing insights into aerodynamic performance and design parameters.

Contribution

It introduces a combined optimization and UVLM approach for shape design of flapping wings, with detailed analysis of parameters affecting flight efficiency.

Findings

Optimized wing shapes improve propulsive efficiency.

Aspect ratio and camber significantly influence performance.

Mesh and time-step selection are crucial for accurate UVLM simulations.

Abstract

The present work is concerned with the shape optimization of flapping wings in forward flight. The analysis is performed by combining a gradient-based optimizer with the unsteady vortex lattice method (UVLM). We describe the UVLM implementation and provide insights on how to select properly the mesh and time-step sizes to achieve invariant UVLM simulation results under further mesh refinement. Our objective is to identify a set of optimized shapes that maximize the propulsive efficiency, defined as the ratio of the propulsive power over the aerodynamic power, under lift, thrust, and area constraints. Several parameters affecting flight performance are investigated and their impact is described. These include the wing's aspect ratio, camber line, and curvature of the leading and trailing edges. This study provides guidance for shape design of engineered flying systems.