Rapid Design Process of Shrouded Rotors for Efficient UAV Propulsion

Abstract

A novel approach for the rapid design of unconventional rotor shrouds combining a rapid manufacturing approach with a high-fidelity CFD prediction tool is proposed in this work. Using 3D printing and thrust stand measurements, different shroud designs have been explored experimentally to evaluate the performance gains of propeller shrouds for multirotor vehicles with small-scale, off-the-shelf propellers. The experimental studies are complimented with 3D quasi-steady CFD simulations to gain further insights into the flow fields for unconventional shroud geometries. The framework has been demonstrated for a commercial 5-inch racing-drone propeller, featuring significant performance gains using NACA-shaped shroud profiles.

An Unsteady Reynolds–Averaged Navier–Stokes–Large Eddy Simulation Study of Propeller–Airframe Interaction in Distributed Electric Propulsion

“…High-resolution unsteady analysis of propeller-fixed wing interaction indicates that the actuator disk model agrees well with the mean lift and drag characteristics of the unsteady flow for most spanwise locations [15]. Other studies of UAVpropeller aerodynamic interaction include those on aero-elastic propeller interaction [16], inviscid flow analysis [17], effects of propeller position on pressure over the wing [18,19], large eddy simulation (LES) studies on tip-vortex shedding [20], detached eddy simulation (DES) studies of a propeller wake [21], quasi-steady 3D numerical studies for shrouded propellers [22], and multiple reference frame (MRF) studies for slow flyer propellers [23]. This encourages us to use the actuator disk approach along with a high-fidelity DES approach to estimate the aerodynamic performance of multi-propeller configurations.…”

Aerodynamic performance of the electric vertical take-off and landing (eVTOL)

“…CFD utilizing Reynolds Averaged Navier Stokes equations has become one of the most efficient and cost-effective tools in recent times. The previous numerous studies [1]- [4] have utilized the Multiple Reference Frame (MRF) approach in CFD to run steady simulations of the flow of a single rotating propeller and predict thrust to validate the accuracy of the numerical solution to experimental data. However, due to the MRF method's inability to consider the relative motion of the moving frame concerning a stationary zone, other studies [5]- [7] utilize a sliding mesh (SM) approach, supported by transient simulation to have the mesh move at a given rate taking into account relative motion.…”