This paper we will consider the sound radiation from a rotor that is partially immersed in a wall boundary layer. Experimental measurements for this configuration have been previously presented by Alexander et al. (2013) and the theoretical framework for the broadband noise prediction, based on a time domain approach, is described by Glegg et al(2014). In this paper we will show results comparing the measurements with predictions. It is found that at low thrust the prediction method works well, but it fails to predict the sound levels at BPF that were measured for the high thrust conditions. RANS calculations of the flow around the propeller clearly identify that this additional sound is caused by a blade vortex interaction that can occur when rotors are located near flat surfaces.
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