Analysis and reduction of blade passing noise of the Entecho Mupod

Rotor - stator interaction has been identified as the dominant noise source of the Mupod, a vertical take - off and landing aircraft, developed by Entecho, a WA company. This paper reports field measurement results of blade passing noise of the Mupod together with its analysis and control. The blade passing event was simulated in a wind tunnel experiment. The flow speed, rotor blade position and rotor stator blade spacing were varied while the chord - wise pressure distribution of the leading surface of the rotor blade was measured by an array of 6 flush mounted microphones. The features of the pressure distribution on the rotor blade influenced by an upstream stator blade were used for the qualitative analysis of the sound radiation from the Mupod. The result of the reduction of the blade passing noise using angled stator blades is also presented.