Control of Interactions between Wake and Blades.

This investigation of rotor-stator interaction noise originated from an interest in reducing a ventilation-noise problem. This type of noise is generated aerodynamically by the flow interaction between the rotor and stator. In order to reduce this interaction noise thoroughly along the pipe, an efficient method is to remove noise sources aerodynamically in the interaction flow region by means of active flow control. This method suggests that we need to identify the active noise source region before attempting to implement the noise reduction. On this account, we shall employ measurement techniques for this identification process by correlating both the interaction-flow field cause and the corresponding acoustic field effect. Therefore, the motive of the present study is to provide a general basis for locating the noise sources experimentally and to pave the road for possible application of the active rotor-stator interaction-noise control in the future.