A fixed-wing VTOL UAV designed around aerodynamic and propulsion requirements, targeting 40+ minutes of endurance while retaining vertical takeoff and landing capability.
- 40+ min
- Endurance target
- 4.76 kg
- Design mass
- 13.7 m/s
- Stall speed
Preliminary Design
Constraint Analysis
Flight requirements were translated into aerodynamic and propulsion constraints before component selection. Wrote a Python analysis tool that evaluates required thrust-to-weight and power-to-weight ratios across wing loading, plotting data and identifying the feasible design point for the aircraft.
A design point within the feasible region was selected:
Wing loading: 60 N/m²
Thrust-to-weight: 1.18
Power-to-weight: 8 W/N
The resulting configuration balances endurance-oriented cruise efficiency with VTOL propulsion margin. The 60 N/m² wing loading supports a low stall speed and efficient cruise, while the 1.18 thrust-to-weight ratio provides 18% excess thrust for vertical flight.
These constraints establish the baseline requirements for the wing, propulsion system, and airframe.
Aerodynamic Wing Design
The SD7062 airfoil was selected for its low-speed lift and endurance characteristics.
Starting from a baseline wing, the geometry was refined using:
- Taper to reduce induced drag
- Washout to promote root-first stall behavior
- Dihedral to improve roll stability
XFLR5 vortex lattice analysis was used to evaluate the aerodynamic effects of each configuration. Wing geometry was iterated to improve lift-to-drag performance and endurance while maintaining similar lift and stability characteristics.
CAD & Structural Layout
The complete airframe was modeled in SolidWorks around a carbon-fiber spar, with four dedicated lift rotors and a separate cruise motor for VTOL and fixed-wing flight.
The internal structure integrates the primary load paths with propulsion, avionics, and payload requirements, providing a foundation for subsequent structural validation and manufacturing.
Aerodynamic & Structural Analysis
ANSYS was used to evaluate aerodynamic loading, structural stresses, and safety margins. The resulting load cases determined the required specifications for the carbon-fiber spar, propulsion system, and other structural components.
Stack
- Python
- XFLR5
- SolidWorks
- Ansys Fluent
- ArduPilot