Mission-driven Rotor Conceptual Design for Future Multi-rotor Vehicles - Application to NASA Dragonfly
Restricted (Penn State Only)
- Author:
- Allred, Gracelyne
- Graduate Program:
- Aerospace Engineering
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- May 01, 2024
- Committee Members:
- Sven Schmitz, Thesis Advisor/Co-Advisor
Jacob Willem Langelaan, Committee Member
Amy Pritchett, Program Head/Chair
Ashwin Renganathan, Committee Member - Keywords:
- CFD
Computational Fluid Dynamics
Rotorcraft
Helicopter
Coaxial Rotor
Multirotor
RotCFD
URANS
Rotor Design
Blade Element Momentum Theory
Urban Air Mobility
Rotor Performance - Abstract:
- The landscape of multi-rotor vehicle design has undergone significant expansion, with increased interest in urban air mobility missions, unique non-terrestrial aircraft applications, and small drone operations. This has driven a need for higher-fidelity analysis to investigate the complex flow patterns surrounding complex rotor configurations. The primary missions for multi-rotor vehicles are being designed with increased diversity in configuration. Traditional hover-centric designs may not be as capable as those optimized for a different flight condition, or those aligning with the mission objectives. This work formulates and implements a mission profile-based weighting method to evaluate rotor performance as applied to the NASA Dragonfly Lander. This metric enabled the comparison of twelve coaxial rotor design variations and the determination of associated sensitivity on rotor performance by various planform parameters. RotorcraftCFD, a hybrid BEMT-URANS flow solver, was utilized to predict coaxial rotor performance. This enabled fast iteration through design variations at a fidelity suitable for preliminary design. Isolated coaxial rotor and two tandem coaxial rotor configurations are analyzed to provide order-of-magnitude information on performance parameter perturbations that drive preliminary design changes. Spacing between coaxial rotor pairs and movement in center of thrust location is explored. Each study detailed is last looked at through the lens of the outlined mission-based weighting system to understand the specific implications for the NASA Dragonfly Lander. Changes in tip shape, twist distribution, and blade thickness were found to most significantly move the rotor design toward its energy consumption goal.