Modelling of Wind Tunnel Wall Effects on the Radiation Characteristics of Acoustic Sources
An important analytical result shows that it is not possible to obtain an accurate directivity in the tunnel environment unless the modal cut off ratio for the source exceeds unity for at least the lowest order mode generated. This result is verified numerically. Acoustic fields and their corresponding directivities in the wind tunnel and free field are compared for situations in which the cut-off condition is satisfied. Several propeller operating conditions and tunnel Mach numbers of M equals 0. 0 and M equals minus 0. 5 are investigated to determine if the number of cut-on modes or the mean flow convective effects have a significant influence on the matching of the tunnel and free field directivities.
W. Eversman and K. J. Baumeister, "Modelling of Wind Tunnel Wall Effects on the Radiation Characteristics of Acoustic Sources," AIAA Paper, American Institute of Aeronautics and Astronautics (AIAA), Jan 1984.
AIAA Paper (1984, Williamsburg, VA, USA)
Mechanical and Aerospace Engineering
Article - Conference proceedings
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