Mutual Interaction Noise in Rotor-Beam Configuration

In small-size UAVs configurations, rotor-beam interaction noise is an important contributor to the tonal noise. With the beam located in the close wake of the rotor, distinct and coupled noise source mechanisms can occur. Both rotor blades and beam radiate sound as both experience unsteady loading due to the presence of each other. The former can be described by a blade-potential interaction noise model; i.e. blades undergo a potential distortion when passing close to the cylindrical beam. Similarly, the latter arises from potential interaction between the blade and the beam; i.e. the beam experiences variation in incoming flow speed and loading when the blade passes above it. In this paper, we combine those models to predict the noise radiated by a rotor-beam configuration and compare our results with experimental and numerical results from previous studies.