Numerical Investigations of Ground Effect of a Quadcopter

The hovering in ground effect (IGE) of a quadcopter is investigated numerically in terms of flow patterns and aerodynamic characteristics with two different rotor configurations with two different rotor-to-rotor distances. A model of variable-pitch-controlled rotors revealed complicated outwash flow patterns around the quadcopter, showing a pronounced directivity, particularly when the rotor-to-rotor distance was shortened. A narrow and intense outwash (jet) region formed between the rotors. A similar outwash pattern was also found in the diagonal plane. Our results further show that the rotor configuration effect on the aerodynamic performance of the quadcopter can vary significantly with changes in altitude from the ground. Moreover, the rotor configuration with a short rotor-to-rotor distance displayed a relationship between aerodynamic characteristics and altitude that was similar to that of a single rotor.