Low Reynolds Number Rotor Blade Aerodynamic Analysis

Maintaining a steady hover flight in a rotorcraft usually requires high energy input. The aim of the paper is to prove that it is possible to vastly reduce energy use in a rotorcraft by reducing the disc loading. The energy consumption reduction is especially important in electric rotorcraft, where the energy source is characterized by low energy density when compared to the hydrocarbon fuel in ICE rotorcraft. The paper presents results of CFD simulations on low Reynolds Number operating rotors. For low RE rotors tip vortex induced drag is highly affecting the rotor’s Figure of Merit, thus reducing rotor performance. Even though FM is reduced, the low RE setup is still beneficial in terms of reduced Power Loading, the main factor responsible for hover endurance.