Comparative wind tunnel evaluation of a bio-inspired corrugated wing
File(s)
Author(s)
Islam, Husnain
Type
Thesis
Abstract
This study presents a comparative wind tunnel evaluation of bio-inspired corrugated dragonfly wings and conventional aerofoils at low Reynolds numbers (Re ≈ 6000 and 10,000), relevant to Micro Air Vehicles (MAVs). Addressing gaps in biomimetic aerodynamic performance, the research investigates how corrugation affects lift, drag, flow separation, and aerodynamic stability across various angles of attack (AOA).
Four wing profiles were tested: a bio-inspired corrugated wing (CG), a hybrid shell aerofoil (SH), a flat plate (FP), and a NACA0002 profile (NA). The wings were parametrically designed and then fabricated using SLA 3D printing, enabling high geometric accuracy at a minimal thickness of 0.4 mm with a flexible resin. Wind tunnel testing was conducted on a small subsonic tunnel, with a custom rig including a dual-axis load cell, to capture static aerodynamic forces and provide insight into flow behaviour via smoke visualization.
At 1.5ms^-1 (Re ≈ 6000), under laminar wind tunnel conditions, CG and SH exhibited the highest lift-to-drag (L/D) efficiency, with CG delaying stall to 25° AOA, compared to NA and FP. At 2.5ms^-1 (Re ≈ 10,000) under low-Re transitional regime, SH outperformed all wings, sustaining attached flow and a smooth stall transition, while CG’s performance plateaued, resembling conventional aerofoils in stall angle. Smoke visualization confirmed that CG and SH maintained flow attachment longer, with CG exhibiting vortex retention effects aiding stability. FP demonstrated flow separation and high drag, reducing aerodynamic efficiency.
The findings suggest that corrugation benefits aerodynamic efficiency at lower speeds, while hybrid shell profiles balance aerodynamic performance and structural feasibility. This comparative result is therefore useful for informing MAV wing design, especially in terms of stability and aerodynamic performance. Future work can extend the analysis to flapping flight conditions to explore the effects of corrugation under unsteady aerodynamics and further optimise wing designs for MAV applications.
Four wing profiles were tested: a bio-inspired corrugated wing (CG), a hybrid shell aerofoil (SH), a flat plate (FP), and a NACA0002 profile (NA). The wings were parametrically designed and then fabricated using SLA 3D printing, enabling high geometric accuracy at a minimal thickness of 0.4 mm with a flexible resin. Wind tunnel testing was conducted on a small subsonic tunnel, with a custom rig including a dual-axis load cell, to capture static aerodynamic forces and provide insight into flow behaviour via smoke visualization.
At 1.5ms^-1 (Re ≈ 6000), under laminar wind tunnel conditions, CG and SH exhibited the highest lift-to-drag (L/D) efficiency, with CG delaying stall to 25° AOA, compared to NA and FP. At 2.5ms^-1 (Re ≈ 10,000) under low-Re transitional regime, SH outperformed all wings, sustaining attached flow and a smooth stall transition, while CG’s performance plateaued, resembling conventional aerofoils in stall angle. Smoke visualization confirmed that CG and SH maintained flow attachment longer, with CG exhibiting vortex retention effects aiding stability. FP demonstrated flow separation and high drag, reducing aerodynamic efficiency.
The findings suggest that corrugation benefits aerodynamic efficiency at lower speeds, while hybrid shell profiles balance aerodynamic performance and structural feasibility. This comparative result is therefore useful for informing MAV wing design, especially in terms of stability and aerodynamic performance. Future work can extend the analysis to flapping flight conditions to explore the effects of corrugation under unsteady aerodynamics and further optimise wing designs for MAV applications.
Version
Open Access
Date Issued
2025-04-09
Date Awarded
01/11/2025
License URL
Advisor
Lin, Huai-Ti
Publisher Department
Department of Bioengineering
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Master of Philosophy (MPhil)