Session: 13-06-01: Applied Mechanics and Materials in Micro- and Nano-Systems

Paper Number: 143363

143363 - Aerodynamic Analysis of a Dielectric Elastomer Membrane in the Gust Environment 

The dynamic interaction between fluid flow and flexible structures is a critical area of research with extensive applications, ranging from aeronautics to renewable energy systems. Specifically, in recent years, the integration of smart materials such as soft, flexible polymeric membrane material in unmanned aerial vehicles (UAVs) involves huge scientific interests in innovative design and development of the wings, which is the most critical element, of UAVs in a variety of applications in weather monitoring, surveillance, and reconnaissance.  The design of a wing of UAVs is very critical for analyzing and enhancing their maneuverability, particularly in the context of turbulent atmospheric conditions, especially in variable gust environments, necessitating advanced design innovations. Recent research has focused on the integration of smart materials into UAV structures, including their wings, to address these challenges. Dielectric elastomer membranes, a subset of electroactive polymers known for their significant strain response to electrical stimuli, are emerging as a promising solution for gust alleviation. These membranes consist of a thin elastomer layer flanked by compliant electrodes. When voltage is applied, the incompressible elastomer contracts in thickness and expands in-plane due to electrostatic pressure, returning to its original form once the voltage is removed. This process modulates the wing's tension, thereby altering its dynamic properties.

This study presents a comprehensive aerodynamic analysis of a dielectric elastomer membrane subjected to variable gust environments, showing its potential to adapt and enhance performance in an unsteady aerodynamic condition. Through the integration of computational fluid dynamics (CFD) and the development of a novel electroactive membrane model, this research exhibits the pathways for optimizing the aerodynamic efficiency and stability of flexible structures in fluctuating airstreams. In this research, the electroactive membrane VHB 4910 is examined, with carbon grease serving as the conductive electrode material on its surfaces. The study addresses the challenges posed by wind gusts, which can create instantaneous, turbulent conditions for UAVs during flight. To assess the impact of the variable gust loads on a flexible membrane wing, this study introduces a variable gust profile alongside two stochastic gust models: the Dryden gust model and the von Karman gust model. The adoption of an electroactive membrane wing emerges as a viable strategy for mitigating the effect of variable gusts. A fluid-structure interaction model, combining the finite element model of the membrane with a computational fluid dynamics model of the surrounding airflow, is developed to study the coupled effect of variable gust and its structural response. Aerodynamic coefficients are derived from forces calculated in numerical simulations for varying gust velocities. Additionally, wind tunnel experiments are conducted to examine the membrane wing's aerodynamic behavior. The Dryden and von Karman gust models demonstrate minimal discrepancies in the gust velocity profile magnitude, validating the fluid-structure interaction model's accuracy in predicting lift coefficients against experimental data.

This study offers valuable insights into the aerodynamics and maneuverability of UAVs in gust environments, contributing to the advancement of UAV design for improved stability and performance under adverse atmospheric conditions. Results from the computational simulations reveal that the electroactive membrane demonstrates significant potential in enhancing aerodynamic performance under variable gust conditions. By actively adjusting its shape in real-time, the membrane effectively reduces drag and increases lift, thereby improving the overall aerodynamic efficiency.  

In conclusion, the aerodynamic analysis of an electroactive membrane in a variable gust environment presented where the integration of dielectric elastomer membrane into aerodynamic structures offers a promising path for enhancing performance and stability in unsteady airflow conditions. This research not only advances the understanding of the interaction between flexible membrane structures and variable fluid flow but also paves the way for the development of innovative adaptive design of unmanned aerial vehicles (UAVs).

Presenting Author: Gazi Raihan University of New Orleans

Presenting Author Biography: Gazi Raihan is a graduate student doing his Ph.D. in Mechanical Engineering at the University of New Orleans. Currently, he is working under Dr. Uttam Chakravarty, a Professor, in the Department of Mechanical Engineering at the University of New Orleans. His current research investigates sandwich material's prospective application and design for wind blades and microelectromechanical devices.

Authors:

Gazi Raihan University of New Orleans
Uttam Chakravarty University of New Orleans