Small unmanned aerial vehicles (sUAVs), and especially multi-rotor crafts, have seen an acceleration in technological development in recent years, as adoption in civilian applications increases. Improving their performance and controllability requires effective control algorithms running onboard the drones, which in turn depend on light and accurate models for the drones' propellers' aerodynamic characteristics. Small drones' propellers operate at low Reynolds numbers ($Re<10^5$), where the physics is very sensitive to geometry and inflow conditions. Furthermore, rapid maneuvers and wind gusts can introduce unsteady aerodynamic effects relevant for the whole drone's flight dynamics. High-fidelity methods like computational fluid dynamics can capture these complex phenomena, but their high computational cost makes them unsuitable for real-time analysis.