Modeling the Effects of Wind Tunnel Wall Absorption on the Acoustic Radiation Characteristics of Propellers
Finite element theory is used to calculate the acoustic field of a propeller in a soft walled circular wind tunnel and to compare the radiation patterns to the same propeller in free space. Parametric solutions are presented for a “Gutin” propeller for a variety of flow Mach numbers, admittance values at the wall, microphone position locations, and propeller to duct radius ratios. Wind tunnel boundary layer is not included in this analysis. For wall admittance nearly equal to the characteristic value of free space, the free field and ducted propeller models agree in pressure level and directionality. In addition, the need for experimentally mapping the acoustic field is discussed.
K. J. Baumeister and W. Eversman, "Modeling the Effects of Wind Tunnel Wall Absorption on the Acoustic Radiation Characteristics of Propellers,", Jan 1986.
Mechanical and Aerospace Engineering
Article - Conference proceedings