Optimization of propellers under consideration of aeroacoustic and aerodynamic goals and installation effects

Urban Air Mobility (UAM) vehicles like air taxis and cargo unmanned aerial vehicles (UAVs) operate close to urban areas, which makes noise an important issue. Cargo UAVs are typically highly integrated in terms of functions, leading to a high extent of aerodynamic interactions between propellers and the airframe. As a result of these installation effects, unsteady loading noise can become the dominant part of the aerial vehicle noise emissions, which leads to a situation where classical propeller noise reduction measures like blade tip Mach number reduction do not necessarily lead to a reduction in the overall noise emissions anymore. Overcoming these uncertainties in propeller design necessitates propeller noise optimization on a propeller configuration level. In this work, an existing propeller optimization framework for isolated propellers was extended by consideration of propeller inflow velocity perturbation due to the propeller installation situation. This way, unsteady loading noise due to aerodynamic installation effects is resolved in a medium-fidelity optimization toolchain. Optimization results of a pusher propeller UAV configuration demonstrate that aircraft noise reductions require configuration level noise optimizations. Furthermore, it is shown how classical noise reduction measures can fall short in reducing installed aircraft propeller noise on a configuration level.     «

Urban Air Mobility (UAM) vehicles like air taxis and cargo unmanned aerial vehicles (UAVs) operate close to urban areas, which makes noise an important issue. Cargo UAVs are typically highly integrated in terms of functions, leading to a high extent of aerodynamic interactions between propellers and the airframe. As a result of these installation effects, unsteady loading noise can become the dominant part of the aerial vehicle noise emissions, which leads to a situation where classical prop...     »