Numerical and experimental validation and comparison of reduced order models for small scale rotor hovering performance prediction

View Video Presentation: https://doi.org/10.2514/6.2022-0154.vid Unmanned Aircraft Systems (UAS) are state of the art in the aerospace industry and are involved in many operations. While initially developed for military purposes, commercial applications with small-scale UAS, such as multicopters, are today frequent. Accurate engineering tools are required to assess the performance of these vehicles and optimize power consumption. Thrust and power curves of rotors used by small-scale UAS are essential to design efficient systems. The lack of experimental data and accurate prediction models to evaluate rotor coefficients over the UAS flight envelope are two substantial limitations in UAS science. In addition, Reynolds numbers based on the chord for small-scale rotors at usual rotation rates are usually smaller than 100,000 resulting in degraded performance. In this paper, we describe two in-house Reduced Order Models (ROM's), namely a Blade Element Momentum (BEM) code and a Non-Linear Lifting Line Theory approach combined with Free Vortex Wake (NLLT-FVW) code. We verify these models with three-dimensional Computational Fluid Dynamics (CFD) simulations, and we validate them with existing experimental data for blades in low Reynolds conditions. We also use two-dimensional CFD simulations to generate the aerodynamic database for the reduced-order models.