A Three-Dimensional Microphone Array for Wind Tunnel Application

摘要

The positions of microphones in arrays are usually distributed two-dimensionally either in a plane or on the surface of a cylinder or sphere. For such two-dimensional arrays, the determination of a point-spread function is well-known and can be used within certain boundaries to optimize arrays in terms of minimizing the effect of side lobes in the beamforming maps. In contrary to the usual two-dimensional array configuration, the present paper outlines the development and implementation of an array for wind tunnel application where the microphones are distributed three-dimensionally. The microphone positions within this array are optimized to reduce the side lobes in three-dimensional space. This approach of using an ab initio three-dimensional distribution shows significant advantage over the combination of multiple planar arrays to form a quasi-three-dimensional microphone arrangement. The technique has been applied to an array for the use in wind tunnel measurements to emphasize the benefits of this approach.