SHAPE OPTIMIZATION OF A FAN DUNCTE FOR A VERTICAL TAKEOFF AND LANDING

Abstract

The popularity of ride sharing services and recent improvements in electric car performance and automation have sparked interest in E-VTOL (Electric Vertical Takeoff and Landing) aircraft for personal transportation. Companies such as Uber, Airbus and EHANG are currently researching such aircraft for transportation over short distances in crowded urban environments. A personal E-VTOL design based on a ducted fan concept is proposed and the vertical lift capability is optimized. A numerical optimization algorithm is coupled with a computational fluid dynamics (CFD) analysis code to perform shape optimization. The objective is to determine the internal and external duct shape that maximizes the vertical force for a given fan speed. Different flow rates of the ducted fan and the propeller are considered. The shape is parameterized using b-splines with control points that are constrained to generate only valid shapes. Pointwise is used to automatically generate a hybrid mesh based on parameters generated by the optimizer. The mesh is then passed to FLUENT, which computes the flow field and calculates the vertical force achieved by the candidate design. The vertical force consists of the aerodynamic lift that is due to static pressure differences and force due to momentum change that is generated by the ducted fan. Results are then passed back to the optimizer for use in generation of the next set of candidate design parameters.