Session: 03-01 Mission-Adaptive Morphing UAVs

Paper Number: 167923

167923 - Evaluating Morphing Wing Penalties Using Aeroelastic Fea: A Computational Framework for Comparing Adaptive and Fixed-Wing Uav Designs Across Multiple Mission Phases 

The ability to morph an aircraft brings increased performance characteristics, such as range and maneuverability, across different flight phases. However, optimizing performance over multiple mission phases is a significant challenge, primarily due to the performance penalties associated with morphing. These penalties typically include increased weight from additional actuators, the need for structural reinforcement to mitigate aeroelastic effects, and elevated power and spatial requirements. Currently, there is a lack of analytical tools that can be used to rapidly and efficiently analyze multiple configurations and morphing strategies to develop optimized morphing UAV designs. This study presents a computational framework to evaluate the trade-offs between adaptive and fixed-wing unmanned aerial vehicles (UAVs) across multiple mission phases in the early stages of a design. The focus of this discussion is the component of the framework that conducts aeroelastic finite element analysis (FEA) to assess the drawbacks of morphing aircraft within a defined scenario.
 

Before consideration of the performance penalties prior analysis must be done in the software frame. A preprocessor first examines a large number of design configurations and then down-selects the best-performing geometries. These best-performing geometries are then passed to a high-fidelity Computational Fluid Dynamics (CFD) analysis that determines the performance metrics (i.e., cruise range, dash range) as well as the pressure fields of each geometry configuration. Design Space Decomposition (DSD) is performed to group designs into adaptive families. These adaptive families are then sorted based on their performance.  Finally, an aeroelastic analysis is performed using the pressure fields from the CFD analysis and morphing families identified through DSD. This analysis optimizes the composite shell of a monocoque wing to minimize the performance penalties typically associated with morphing.
 

The finite element analysis of the morphing configurations suitable for the given environment yields an optimized composite layup to minimize stress, deflection, and mass. From the FEA analysis the minimum forces required to actuate any morphing components is calculated. This information is used in an analytical evaluation of the average mass and volume of typical morphing components, such as actuators, given the applied reaction force from the FEA analysis. The data on the actuator metrics is incorporated into the final penalty determination after determining the optimized composite layup. The evaluation of morphing penalties provides engineers with insights into the feasibility of adaptive wing designs in specific flight conditions. By quantifying both the benefits of morphing concepts and the associated penalties, this aeroelastic analysis in the morphing design trade-off software package enables engineers to assess whether a morphing wing is a more advantageous choice than a fixed-wing or quadcopter design. This software systematically generalizes morphing penalties, offering a structured approach to assess the necessary requirements for justifying a morphing wing over a fixed-wing alternative.

Presenting Author: Darren Hartl Texas A&M Univ.

Presenting Author Biography: Dr. Hartl has held joint appointments at the Air Force Research Laboratory as a contracted Research Scientist in the Materials and Manufacturing Directorate and as a Visiting Researcher in the Aerospace Systems Directorate. His work has bridged the topics of advanced multifunctional material systems and their integration into aerospace platforms using genotype–phenotype topological approaches. He is an Associate Professor in the Department of Aerospace Engineering at Texas A&M. His team works on projects ranging from self-folding origami-based structures to self-regulating morphing radiators for spacecraft to advanced actuators for avian-inspired aircraft. Darren has over 15 years of experience working with Shape Memory Alloys (SMAs) and morphing structures. His efforts have included both experimental and theoretical studies and he has worked collaboratively with both governmental and industrial sponsors considering medical, oil exploration, aeronautical, and space-related applications. In his previous appointment as Assistant Director of the Aerospace Vehicle Systems Institute, he has also served the world’s major airframe and propulsion companies in collaboration with governmental agencies to develop novel joint research and development programs benefitting from a common industry voice, including the first ever effort to establish aerospace standards toward the flight certification of shape memory alloys.