Quantification of wake interaction effects on multi-rotor configurations in forward flight.

This study aims to illustrate the correlations of performance and wake dynamics in multi-rotor configurations and explain the induced circulation (IC), the quantification factor for wake interactions. A series of parametric studies are performed considering cross- and plus-type quadrotors to analyze the aerodynamic and aeroacoustic characteristics. The performance and tip vortex structure of each rotor are different according to each interaction relation. Total circulation is classified into the rotor-, wake-, and motion-induced components using the IC concept. Overall, the wake- and motion-IC primarily influence the rotor performance; however, the interaction effect is negligible as the advance ratio and incidence angle increase. In this study, the complex wake dynamics of multi-rotors are classified in terms of each interaction component. The physical relations of performance, wake dynamics, and IC can be fundamental steps toward wake interaction models for multi-rotor configurations. [ABSTRACT FROM AUTHOR]