Aerodynamic Performance of the Three-Dimensional Lumped Flexibility Bionic Hovering Wing

Zhu Jianyang,Jiang Lin,Hou Yu

doi:10.1155/2018/1314258

Zhu Jianyang, Jiang Lin + Show 1 more

Open Access

https://doi.org/10.1155/2018/1314258

Copy DOI

Abstract

Understanding the effect of flexibility on the aerodynamic characteristics of the wing is one of the most important considerations for successfully designing a flapping wing micro aero vehicle (FMAV). This paper aims at providing a systematic synthesis on the flexibility effects on the hovering performance of the bionic wing based on the numerical analysis approach. We construct a novel three-dimensional bionic wing, which has lumped flexibility at the root, and develop an iterative coupling program to simulate the interaction between the flexible wing and fluid. The effects of flexibility on the hovering performance of the three-dimensional flapping wing are investigated, and the results indicate that the best performance of the wing is achieved when the wing flaps at resonance and has the density close to the natural insect wing. The feasibility of using lumped flexibility wings driven by a simple harmonic flapping for designing efficient FMAV is also concluded in this study.

Highlights

Flapping wing aero vehicle has become a popular research topic in recent years because it has better aerodynamic performance than the fixed-wing and rotary-wing aero vehicle under low Reynolds number flight regime [1,2,3]
The 3D rigid and lumped flexibility bionic hovering wing are performed with θm = π/3, f = 120 Hz, and Re = 2347, and the parameters of the lumped flexibility wing are characterized by frequency ratio f ∗ and density ratio ρ∗
A novel three-dimensional bionic wing which has lumped flexibility at the root is constructed; a numerical experiment is carried out to investigate the flexibility effects on the hovering performance of this novel bionic wing, where the incompressible Navier-Stokes (N-S) equations coupled with passive pitching motion by aerodynamic torque is solved

Summary

Introduction

Flapping wing aero vehicle has become a popular research topic in recent years because it has better aerodynamic performance than the fixed-wing and rotary-wing aero vehicle under low Reynolds number flight regime [1,2,3]. It was found that the studied wing can generate sufficient lift force to support the insect’s weight They concluded that the pitching motion can be passive in the dipteran’s flapping flight. Later, they again experimentally and numerically [9, 10] investigated the performance of the three-dimensional lumped flexible wing, and it was found that if the wing has appropriate flexibility, the lumped flexible wing can generate sufficient lift force to support the corresponding insect weight. Michelin and Llewellyn Smith [11] studied the influence of the flexibility on the performance of a heaving wing They found that the maximum values of the mean thrust and efficiency are obtained when the resonance occurs between the forcing frequency and a natural frequency of the system. Masoud and Alexeev [12] conducted a numerical study to focus on the aerodynamic characteristics of a flexible planar hovering wing which was flapped at resonance

Objectives

Methods

Results

Conclusion